Hide QFont::cacheStatistics which isn't available in QWS

Signed-off-by: Sergey Kostanbaev <sergey.kostanbaev@gmail.com>
---

diff -ur PyQt-x11-gpl-4.9.6/sip/QtGui/qfont.sip pyqt-4.9.6/sip/QtGui/qfont.sip
--- PyQt-x11-gpl-4.9.6/sip/QtGui/qfont.sip	2012-12-08 13:51:38.000000000 +0400
+++ pyqt-4.9.6/sip/QtGui/qfont.sip	2013-05-22 14:06:38.335000022 +0400
@@ -185,7 +185,9 @@
 %End
     static void initialize();
     static void cleanup();
+%If (!WS_QWS)
     static void cacheStatistics();
+%End
     QString defaultFamily() const;
     QString lastResortFamily() const;
     QString lastResortFont() const;