Fix FTBFS with libfreetype6 >= 2.5.x

This resolves Bug 1765
(cherry picked from commit 1ee1ffbae6)

config.tests/x11/xfreetype.test

@@ -116,12 +116,15 @@ fi
 # check for freetype2 headers
 FREETYPE2_INCDIR=
 if [ "$XFT" = "yes" ]; then
-    INC="freetype2/freetype/freetype.h"
     XDIRS=`sed -n -e '/^QMAKE_INCDIR_X11[	]*=/ { s/[^=]*=[	 ]*//; s/-I/ /g; p; }' $XCONFIG`
     LDIRS=`sed -n -e '/^QMAKE_INCDIR[	]*=/ { s/[^=]*=[	 ]*//; s/-I/ /g; p; }' $XCONFIG`
     INCDIRS="$IN_INCDIRS $XDIRS $LDIRS /usr/include /include"
     F=
     for INCDIR in $INCDIRS; do
+	INC="freetype2/freetype/freetype.h"  # libfreetype <= 2.4.9-1.1
+	if ! [ -f $INCDIR/$INC ]; then
+	    INC="freetype2/freetype.h"  # libfreetype >= 2.5.1-1
+	fi
 	if [ -f $INCDIR/$INC ]; then
 	    # detect major version of freetype2
 	    FREETYPE_MAJOR=`grep "#define FREETYPE_MAJOR" $INCDIR/$INC | head -n 1 | awk '{ print \$3 }'`