Fix namespace compilation.

Change-Id: Id8d71a48df20da16647834e8f9732012f26f928f
Reviewed-by: Michael Goddard <michael.goddard@nokia.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@nokia.com>

src/plugins/gstreamer/mediaplayer/qgstreamerplayercontrol.h

@@ -50,9 +50,10 @@
 
 #include <limits.h>
 
+QT_BEGIN_NAMESPACE
+
 class QMediaPlayerResourceSetInterface;
 
-QT_BEGIN_NAMESPACE
 class QMediaPlaylist;
 class QMediaPlaylistNavigator;
 class QSocketNotifier;