Fixed compile error (seen on OS/2).

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_2_4_BRANCH@23155 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

src/common/intl.cpp

@@ -1268,7 +1268,7 @@ wxString wxLocale::GetSystemEncodingName()
     // to Unix98)
     char *oldLocale = strdup(setlocale(LC_CTYPE, NULL));
     setlocale(LC_CTYPE, "");
-    char *alang = nl_langinfo(CODESET);
+    const char *alang = nl_langinfo(CODESET);
     setlocale(LC_CTYPE, oldLocale);
     free(oldLocale);