correct small errors in wxqt implementation

src/qt/window.cpp

@@ -1109,6 +1109,7 @@ bool wxWindowQt::QtHandlePaintEvent ( QWidget *handler, QPaintEvent *event )
 
                 // send the paint event (wxWindowDC will draw directly):
                 wxPaintEvent paint( GetId() );
+                paint.SetEventObject(this);
                 handled = ProcessWindowEvent(paint);
                 m_updateRegion.Clear();
             }