Fix installation of class headers

Since Qt 5.11 (see commit [1]), the key word HEADER_CLASSES has been
removed. It has been replaced by a new variable GENERATED_HEADER_FILES.

The class headers were not generated, this commit moves them directly to
HEADER_FILES.

[1]: https://github.com/qt/qtbase/commit/9c4c136bc9f29bab1cc9684dfced55a92a8bbe96

Signed-off-by: Gaël PORTAY <gael.portay@savoirfairelinux.com>
diff -Nurd qtwebkit-opensource-src-5.9.1.orig/include/QtWebKit/headers.pri qtwebkit-opensource-src-5.9.1/include/QtWebKit/headers.pri
--- qtwebkit-opensource-src-5.9.1.orig/include/QtWebKit/headers.pri	2018-06-29 09:21:06.395038976 -0400
+++ qtwebkit-opensource-src-5.9.1/include/QtWebKit/headers.pri	2018-06-29 17:37:52.500020060 -0400
@@ -1,5 +1,4 @@
-SYNCQT.HEADER_FILES = WebKit/qt/Api/qwebdatabase.h WebKit/qt/Api/qwebelement.h WebKit/qt/Api/qwebhistory.h WebKit/qt/Api/qwebhistoryinterface.h WebKit/qt/Api/qwebkitglobal.h WebKit/qt/Api/qwebkitplatformplugin.h WebKit/qt/Api/qwebpluginfactory.h WebKit/qt/Api/qwebsecurityorigin.h WebKit/qt/Api/qwebsettings.h ../include/QtWebKit/qtwebkitversion.h ../include/QtWebKit/QtWebKit 
-SYNCQT.HEADER_CLASSES = ../include/QtWebKit/QWebDatabase ../include/QtWebKit/QWebElement ../include/QtWebKit/QWebElementCollection ../include/QtWebKit/QWebHistoryItem ../include/QtWebKit/QWebHistory ../include/QtWebKit/QWebHistoryInterface ../include/QtWebKit/QWebSelectData ../include/QtWebKit/QWebSelectMethod ../include/QtWebKit/QWebNotificationData ../include/QtWebKit/QWebNotificationPresenter ../include/QtWebKit/QWebHapticFeedbackPlayer ../include/QtWebKit/QWebTouchModifier ../include/QtWebKit/QWebFullScreenVideoHandler ../include/QtWebKit/QWebSpellChecker ../include/QtWebKit/QWebKitPlatformPlugin ../include/QtWebKit/QWebPluginFactory ../include/QtWebKit/QWebSecurityOrigin ../include/QtWebKit/QWebSettings ../include/QtWebKit/QtWebKitVersion 
+SYNCQT.HEADER_FILES = WebKit/qt/Api/qwebdatabase.h WebKit/qt/Api/qwebelement.h WebKit/qt/Api/qwebhistory.h WebKit/qt/Api/qwebhistoryinterface.h WebKit/qt/Api/qwebkitglobal.h WebKit/qt/Api/qwebkitplatformplugin.h WebKit/qt/Api/qwebpluginfactory.h WebKit/qt/Api/qwebsecurityorigin.h WebKit/qt/Api/qwebsettings.h ../include/QtWebKit/qtwebkitversion.h ../include/QtWebKit/QtWebKit ../include/QtWebKit/QWebDatabase ../include/QtWebKit/QWebElement ../include/QtWebKit/QWebElementCollection ../include/QtWebKit/QWebHistoryItem ../include/QtWebKit/QWebHistory ../include/QtWebKit/QWebHistoryInterface ../include/QtWebKit/QWebSelectData ../include/QtWebKit/QWebSelectMethod ../include/QtWebKit/QWebNotificationData ../include/QtWebKit/QWebNotificationPresenter ../include/QtWebKit/QWebHapticFeedbackPlayer ../include/QtWebKit/QWebTouchModifier ../include/QtWebKit/QWebFullScreenVideoHandler ../include/QtWebKit/QWebSpellChecker ../include/QtWebKit/QWebKitPlatformPlugin ../include/QtWebKit/QWebPluginFactory ../include/QtWebKit/QWebSecurityOrigin ../include/QtWebKit/QWebSettings ../include/QtWebKit/QtWebKitVersion 
 SYNCQT.PRIVATE_HEADER_FILES = WebKit/qt/Api/qhttpheader_p.h WebKit/qt/Api/qwebdatabase_p.h WebKit/qt/Api/qwebelement_p.h WebKit/qt/Api/qwebhistory_p.h WebKit/qt/Api/qwebplugindatabase_p.h WebKit/qt/Api/qwebscriptworld.h WebKit/qt/Api/qwebscriptworld_p.h WebKit/qt/Api/qwebsecurityorigin_p.h WebKit2/UIProcess/API/qt/qquicknetworkreply_p.h WebKit2/UIProcess/API/qt/qquicknetworkrequest_p.h WebKit2/UIProcess/API/qt/qquickurlschemedelegate_p.h WebKit2/UIProcess/API/qt/qquickwebpage_p.h WebKit2/UIProcess/API/qt/qquickwebpage_p_p.h WebKit2/UIProcess/API/qt/qquickwebview_p.h WebKit2/UIProcess/API/qt/qquickwebview_p_p.h WebKit2/UIProcess/API/qt/qtwebsecurityorigin_p.h WebKit2/UIProcess/API/qt/qwebchannelwebkittransport_p.h WebKit2/UIProcess/API/qt/qwebdownloaditem_p.h WebKit2/UIProcess/API/qt/qwebdownloaditem_p_p.h WebKit2/UIProcess/API/qt/qwebiconimageprovider_p.h WebKit2/UIProcess/API/qt/qwebkittest_p.h WebKit2/UIProcess/API/qt/qwebloadrequest_p.h WebKit2/UIProcess/API/qt/qwebnavigationhistory_p.h WebKit2/UIProcess/API/qt/qwebnavigationhistory_p_p.h WebKit2/UIProcess/API/qt/qwebnavigationrequest_p.h WebKit2/UIProcess/API/qt/qwebpermissionrequest_p.h WebKit2/UIProcess/API/qt/qwebpreferences_p.h WebKit2/UIProcess/API/qt/qwebpreferences_p_p.h WebKit2/UIProcess/API/qt/raw/qrawwebview_p.h WebKit2/UIProcess/API/qt/raw/qrawwebview_p_p.h WebKit2/UIProcess/API/qt/tests/bytearraytestdata.h WebKit2/UIProcess/API/qt/tests/testwindow.h WebKit2/UIProcess/API/qt/tests/util.h 
 SYNCQT.INJECTED_PRIVATE_HEADER_FILES = 
 SYNCQT.QPA_HEADER_FILES = 
diff -Nurd qtwebkit-opensource-src-5.9.1.orig/include/QtWebKitWidgets/headers.pri qtwebkit-opensource-src-5.9.1/include/QtWebKitWidgets/headers.pri
--- qtwebkit-opensource-src-5.9.1.orig/include/QtWebKitWidgets/headers.pri	2018-06-29 09:21:06.391705602 -0400
+++ qtwebkit-opensource-src-5.9.1/include/QtWebKitWidgets/headers.pri	2018-06-29 17:38:47.660648435 -0400
@@ -1,5 +1,4 @@
-SYNCQT.HEADER_FILES = WebKit/qt/WidgetApi/qgraphicswebview.h WebKit/qt/WidgetApi/qwebframe.h WebKit/qt/WidgetApi/qwebinspector.h WebKit/qt/WidgetApi/qwebpage.h WebKit/qt/WidgetApi/qwebview.h ../include/QtWebKitWidgets/qtwebkitwidgetsversion.h ../include/QtWebKitWidgets/QtWebKitWidgets 
-SYNCQT.HEADER_CLASSES = ../include/QtWebKitWidgets/QGraphicsWebView ../include/QtWebKitWidgets/QWebHitTestResult ../include/QtWebKitWidgets/QWebFrame ../include/QtWebKitWidgets/QWebInspector ../include/QtWebKitWidgets/QWebPage ../include/QtWebKitWidgets/QWebView ../include/QtWebKitWidgets/QtWebKitWidgetsVersion 
+SYNCQT.HEADER_FILES = WebKit/qt/WidgetApi/qgraphicswebview.h WebKit/qt/WidgetApi/qwebframe.h WebKit/qt/WidgetApi/qwebinspector.h WebKit/qt/WidgetApi/qwebpage.h WebKit/qt/WidgetApi/qwebview.h ../include/QtWebKitWidgets/qtwebkitwidgetsversion.h ../include/QtWebKitWidgets/QtWebKitWidgets ../include/QtWebKitWidgets/QGraphicsWebView ../include/QtWebKitWidgets/QWebHitTestResult ../include/QtWebKitWidgets/QWebFrame ../include/QtWebKitWidgets/QWebInspector ../include/QtWebKitWidgets/QWebPage ../include/QtWebKitWidgets/QWebView ../include/QtWebKitWidgets/QtWebKitWidgetsVersion 
 SYNCQT.PRIVATE_HEADER_FILES = WebKit/qt/WidgetApi/qwebframe_p.h WebKit/qt/WidgetApi/qwebinspector_p.h WebKit/qt/WidgetApi/qwebpage_p.h WebKit/qt/WidgetApi/qwebviewaccessible_p.h 
 SYNCQT.INJECTED_PRIVATE_HEADER_FILES = 
 SYNCQT.QPA_HEADER_FILES =