fixed the menu bug introduced by the previous commit

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@14768 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/gtk/menuitem.h

@@ -62,7 +62,7 @@ public:
 
 private:
     // common part of all ctors
-    void Init();
+    void Init(const wxString& text);
 
     // DoSetText() transforms the accel mnemonics in our label from MSW/wxWin
     // style to GTK+ and is called from ctor and SetText()