fix memory leak; allocate the DC before SetFont() is called on the status bar

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@58788 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/msw/statusbar.h

@@ -26,6 +26,7 @@ public:
                 long style = wxST_SIZEGRIP,
                 const wxString& name = wxStatusBarNameStr)
     {
+        m_pDC = NULL;
         (void)Create(parent, id, style, name);
     }