Fix missing override warning for android

This amends 8447f5f006.

Change-Id: Idd25c13735539682f6034724df4c79fcf10a1810
Reviewed-by: BogDan Vatra <bogdan@kdab.com>

src/plugins/platforms/android/qandroidplatformmenubar.h

@@ -61,7 +61,7 @@ public:
     void handleReparent(QWindow *newParentWindow) override;
     QPlatformMenu *menuForTag(quintptr tag) const override;
 
-    QWindow *parentWindow() const;
+    QWindow *parentWindow() const override;
     PlatformMenusType menus() const;
     QMutex *menusListMutex();