Clang: Sync ClangProjectSettingsWidget to changed settings

Change-Id: Ic123c8a3b10a18d9f9313462a682c470eb3ffdaf
Reviewed-by: Ivan Donchevskii <ivan.donchevskii@qt.io>

src/plugins/clangcodemodel/clangprojectsettingswidget.h

@@ -48,6 +48,9 @@ private:
     void onDelayedTemplateParseClicked(bool);
     void onGlobalCustomChanged(int index);
     void onAboutToSaveProjectSettings();
+
+    void syncWidgets();
+    void syncGlobalCustomComboBox();
     void syncOtherWidgetsToComboBox();
 
     void refreshDiagnosticConfigsWidgetFromSettings();