Fix regex errors thrown by Perl 5.26:

Unescaped left brace in regex is illegal here in regex; marked by <-- HERE in m/^(.*)\${ <-- HERE ?([A-Z_]+)}?(.*)$/ at $BUILDROOT/host/usr/bin/intltool-update line 1065.

Fetched from:
https://github.com/Alexpux/MSYS2-packages/blob/master/intltool/perl-5.22-compatibility.patch

Reported upstream:
https://bugs.launchpad.net/intltool/+bug/1696658

Signed-off-by: Jörg Krause <joerg.krause@embedded.rocks>

--- intltool-0.51.0.orig/intltool-update.in	2015-03-09 02:39:54.000000000 +0100
+++ intltool-0.51.0.orig/intltool-update.in	2015-06-19 01:52:07.171228154 +0200
@@ -1062,7 +1062,7 @@ 
 	}
     }
 
-    if ($str =~ /^(.*)\${?([A-Z_]+)}?(.*)$/)
+    if ($str =~ /^(.*)\$\{?([A-Z_]+)}?(.*)$/)
     {
 	my $rest = $3;
 	my $untouched = $1;
@@ -1190,10 +1190,10 @@ 
 	$name    =~ s/\(+$//g;
 	$version =~ s/\(+$//g;
 
-	$varhash{"PACKAGE_NAME"} = $name if (not $name =~ /\${?AC_PACKAGE_NAME}?/);
-	$varhash{"PACKAGE"} = $name if (not $name =~ /\${?PACKAGE}?/);
-	$varhash{"PACKAGE_VERSION"} = $version if (not $name =~ /\${?AC_PACKAGE_VERSION}?/);
-	$varhash{"VERSION"} = $version if (not $name =~ /\${?VERSION}?/);
+	$varhash{"PACKAGE_NAME"} = $name if (not $name =~ /\$\{?AC_PACKAGE_NAME}?/);
+	$varhash{"PACKAGE"} = $name if (not $name =~ /\$\{?PACKAGE}?/);
+	$varhash{"PACKAGE_VERSION"} = $version if (not $name =~ /\$\{?AC_PACKAGE_VERSION}?/);
+	$varhash{"VERSION"} = $version if (not $name =~ /\$\{?VERSION}?/);
     }
 
     if ($conf_source =~ /^AC_INIT\(([^,\)]+),([^,\)]+)[,]?([^,\)]+)?/m)
@@ -1219,11 +1219,11 @@ 
 	$version =~ s/\(+$//g;
         $bugurl  =~ s/\(+$//g if (defined $bugurl);
 
-	$varhash{"PACKAGE_NAME"} = $name if (not $name =~ /\${?AC_PACKAGE_NAME}?/);
-	$varhash{"PACKAGE"} = $name if (not $name =~ /\${?PACKAGE}?/);
-	$varhash{"PACKAGE_VERSION"} = $version if (not $name =~ /\${?AC_PACKAGE_VERSION}?/);
-	$varhash{"VERSION"} = $version if (not $name =~ /\${?VERSION}?/);
-        $varhash{"PACKAGE_BUGREPORT"} = $bugurl if (defined $bugurl and not $bugurl =~ /\${?\w+}?/);
+	$varhash{"PACKAGE_NAME"} = $name if (not $name =~ /\$\{?AC_PACKAGE_NAME}?/);
+	$varhash{"PACKAGE"} = $name if (not $name =~ /\$\{?PACKAGE}?/);
+	$varhash{"PACKAGE_VERSION"} = $version if (not $name =~ /\$\{?AC_PACKAGE_VERSION}?/);
+	$varhash{"VERSION"} = $version if (not $name =~ /\$\{?VERSION}?/);
+        $varhash{"PACKAGE_BUGREPORT"} = $bugurl if (defined $bugurl and not $bugurl =~ /\$\{?\w+}?/);
     }
 
     # \s makes this not work, why?