Remove widget pointer from SettingsTabController

The pointer is not needed and is an anti pattern.

src/tabcontrollers/SettingsTabController.h

@@ -20,7 +20,6 @@ class SettingsTabController : public QObject
 
 private:
     OverlayController* parent;
-    QQuickWindow* widget;
 
     unsigned settingsUpdateCounter = 0;
 
@@ -29,7 +28,7 @@ private:
 
 public:
     void initStage1();
-    void initStage2( OverlayController* parent, QQuickWindow* widget );
+    void initStage2( OverlayController* parent );
 
     void eventLoopTick();