QmlDesigner property editor: we have to hide the non active widget

src/plugins/qmldesigner/components/propertyeditor/basicwidgets.cpp

@@ -789,6 +789,7 @@ void WidgetLoader::setSource(const QUrl &source)
 
     if (m_widget) {
         //m_widget->deleteLater();
+        m_widget->hide();
         m_widget = 0;
     }