fix for menu helpstring in the status bar for MDI child frames

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_2_BRANCH@7158 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk1/mdi.h

@@ -152,9 +152,10 @@ public:
     
     virtual bool IsTopLevel() const { return FALSE; }
     
-    void OnActivate( wxActivateEvent &event );
+    void OnActivate( wxActivateEvent& event );
+    void OnMenuHighlight( wxMenuEvent& event );
     
-  // implementation
+    // implementation
   
     wxMenuBar         *m_menuBar;
     GtkNotebookPage   *m_page;