nest quickwidgets into the opengl conditional

the qtHaveModule(quick) could have of course not worked at this point.

Task-number: QTBUG-38202
Change-Id: Id0270d445b9b82731209d69a9dc1950c03c26781
Reviewed-by: Simon Hausmann <simon.hausmann@digia.com>

src/src.pro

@@ -8,6 +8,8 @@ qtHaveModule(gui):contains(QT_CONFIG, opengl(es1|es2)?) {
         quick \
         qmltest \
         particles
+
+    qtHaveModule(widgets): SUBDIRS += quickwidgets
 }
 
 SUBDIRS += \
@@ -15,6 +17,4 @@ SUBDIRS += \
     imports \
     qmldevtools
 
-qtHaveModule(quick):qtHaveModule(widgets): SUBDIRS += quickwidgets
-
 qmldevtools.CONFIG = host_build