fixed a design flaw in wxFontMapper that prevented automatic creation of wxConfig instance

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@10862 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

include/wx/fontmap.h

@@ -166,6 +166,7 @@ protected:
 #if wxUSE_CONFIG
     // config object and path (in it) to use
     wxConfigBase *m_config;
+    bool m_configIsDummy;
 #endif
 
     wxString  m_configRootPath;