Fix the worst part of http://bugzilla.lyx.org/show_bug.cgi?id=5409 .

git-svn-id: svn://svn.lyx.org/lyx/lyx-devel/trunk@27153 a592a061-630c-0410-9148-cb99ea01b6c8

src/frontends/qt4/TocWidget.cpp

@@ -65,6 +65,8 @@ TocWidget::TocWidget(GuiView & gui_view, QWidget * parent)
 	// Make sure the buttons are disabled when first shown without a loaded
 	// Buffer.
 	enableControls(false);
+
+	init(QString());
 }