qt4: delete the QApplication when we are finished using it, removes an ugly...

qt4: delete the QApplication when we are finished using it, removes an ugly QObject::killTimers warning.

modules/gui/qt4/qt4.cpp

@@ -279,6 +279,7 @@ static void Init( intf_thread_t *p_intf )
 
     /* Launch */
     app->exec();
+    delete app;
 
     /* And quit */
     MainInputManager::killInstance();