fixed gcc warnings about not calling base class ctor explicitly in copy ctors (patch 1028986)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29170 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/icon.h

@@ -49,7 +49,7 @@ public:
     wxIcon() { }
 
         // copy
-    wxIcon(const wxIcon& icon) { Ref(icon); }
+    wxIcon(const wxIcon& icon) : wxGDIImage(icon) { Ref(icon); }
 
         // from raw data
     wxIcon(const char bits[], int width, int height);