Fix namespace compilation.

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

src/multimedia/gsttools_headers/qgstappsrc_p.h

@@ -49,6 +49,8 @@
 #include <gst/app/gstappsrc.h>
 #include <gst/app/gstappbuffer.h>
 
+QT_BEGIN_NAMESPACE
+
 class QGstAppSrc  : public QObject
 {
     Q_OBJECT
@@ -103,4 +105,6 @@ private:
     bool m_forceData;
 };
 
+QT_END_NAMESPACE
+
 #endif