Indicate that EnableCloseButton is virtual.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@42541 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/toplevel.h

@@ -70,7 +70,7 @@ public:
 
     // wxMSW only: EnableCloseButton(false) may be used to remove the "Close"
     // button from the title bar
-    bool EnableCloseButton(bool enable = true);
+    virtual bool EnableCloseButton(bool enable = true);
 
     // Set window transparency if the platform supports it
     virtual bool SetTransparent(wxByte alpha);