ENH: Fix #7784. Fix link of glib when needed.

Modules/FindQt4.cmake

@@ -1586,15 +1586,16 @@ IF (QT4_QMAKE_FOUND)
 
       FIND_LIBRARY(QT_GLIB_LIBRARY NAMES glib-2.0 PATHS ${_glib_query_output} )
       FIND_LIBRARY(QT_GTHREAD_LIBRARY NAMES gthread-2.0 PATHS ${_glib_query_output} )
-
-      IF(QT_GLIB_LIBRARY AND QT_GTHREAD_LIBRARY)
-        SET(QT_QTCORE_LIB_DEPENDENCIES ${QT_QTCORE_LIB_DEPENDENCIES}
-            ${QT_GTHREAD_LIBRARY} ${QT_GLIB_LIBRARY})
-      ENDIF(QT_GLIB_LIBRARY AND QT_GTHREAD_LIBRARY)
-
+    
       MARK_AS_ADVANCED(QT_GLIB_LIBRARY)
       MARK_AS_ADVANCED(QT_GTHREAD_LIBRARY)
     ENDIF(NOT QT_GLIB_LIBRARY OR NOT QT_GTHREAD_LIBRARY)
+
+    IF(QT_GLIB_LIBRARY AND QT_GTHREAD_LIBRARY)
+      SET(QT_QTCORE_LIB_DEPENDENCIES ${QT_QTCORE_LIB_DEPENDENCIES}
+          ${QT_GTHREAD_LIBRARY} ${QT_GLIB_LIBRARY})
+    ENDIF(QT_GLIB_LIBRARY AND QT_GTHREAD_LIBRARY)
+
   ENDIF(QT_QCONFIG MATCHES "glib")
   
   ## clock-monotonic, just see if we need to link with rt