Added missing ctor for wxBitmap using wxIcon for wxQT (taken from wxOSX)

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@78347 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/qt/bitmap.h

@@ -29,6 +29,9 @@ public:
     wxBitmap(const wxString &filename, wxBitmapType type = wxBITMAP_TYPE_XPM);
     wxBitmap(const wxImage& image, int depth = wxBITMAP_SCREEN_DEPTH);
     
+    // Convert from wxIcon
+    wxBitmap(const wxIcon& icon) { CopyFromIcon(icon); }
+
     static void InitStandardHandlers();
 
     virtual bool Create(int width, int height, int depth = wxBITMAP_SCREEN_DEPTH);