[libdbusmenuqt] Fix memory leak
QAction is not a widged, so it is not possible to set it as a parent of QMenu. As a result, QMenu assigned to QAction is not automatically deleted when action is removed from menu and/or deleted.
QAction is not a widged, so it is not possible to set it as a parent of QMenu. As a result, QMenu assigned to QAction is not automatically deleted when action is removed from menu and/or deleted.