fixing missing return value

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66304 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/osx/core/private.h

@@ -151,7 +151,7 @@ public :
                        wxMenu *pSubMenu );
     
     // handle OS specific menu items if they weren't handled during normal processing
-    virtual bool DoDefault() {} ;
+    virtual bool DoDefault() { return false; }
 protected :
     wxMenuItem* m_peer;