FancyMainWindow: Use auto-hiding dock title bars

Instead of the manual hard-to-discover "Locked" action

Change-Id: I08e3b65d3e620adfa1439a8de6e028ecfbdec16d
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/debugger/debuggerplugin.cpp

@@ -2626,7 +2626,6 @@ void DebuggerPluginPrivate::createNewDock(QWidget *widget)
 {
     QDockWidget *dockWidget =
         m_mainWindow->createDockWidget(CppLanguage, widget);
-    dockWidget->setWindowTitle(widget->windowTitle());
     dockWidget->setFeatures(QDockWidget::DockWidgetClosable);
     dockWidget->show();
 }