Qt: correctly fallback to filename when empty tags

(cherry picked from commit 6acd0f4c)
Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

modules/gui/qt4/input_manager.cpp

@@ -474,7 +474,7 @@ void InputManager::UpdateName()
     free( formated );
 
     /* If we have Nothing */
-    if( name.isEmpty() )
+    if( name.simplified().isEmpty() )
     {
         char *uri = input_item_GetURI( input_GetItem( p_input ) );
         char *file = uri ? strrchr( uri, '/' ) : NULL;