fixes for harmless mingw32 warnings

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@29157 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/config.cpp

@@ -352,7 +352,7 @@ wxString wxExpandEnvVars(const wxString& str)
 
           // check the closing bracket
           if ( bracket != Bracket_None ) {
-            if ( m == str.Len() || str[m] != (char)bracket ) {
+            if ( m == str.Len() || str[m] != (wxChar)bracket ) {
               // under MSW it's common to have '%' characters in the registry
               // and it's annoying to have warnings about them each time, so
               // ignroe them silently if they are not used for env vars