Skip tst_QGraphicsProxyWidget::deleteProxyForChildWidget on Win

This tests crashes a lot lately.

Task-number: QTBUG-29684

Change-Id: I6892238dc071f050b0208dd5b4843629fa707347
Reviewed-by: Sergio Ahumada <sergio.ahumada@digia.com>

tests/auto/widgets/graphicsview/qgraphicsproxywidget/tst_qgraphicsproxywidget.cpp

@@ -3154,6 +3154,10 @@ void tst_QGraphicsProxyWidget::actionsContextMenu()
 
 void tst_QGraphicsProxyWidget::deleteProxyForChildWidget()
 {
+#if defined(Q_OS_WIN)
+    QSKIP("This test is crashing on windows, it needs to be fixed. QTBUG-29684");
+#endif
+
     QDialog dialog;
     dialog.resize(320, 120);
     dialog.move(80, 40);