sync back up again with sofia tree prior to their release

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@4177 d0543943-73ff-0310-b7d9-9358b9ac24b2

libs/sofia-sip/libsofia-sip-ua/sip/validator.c

@@ -180,7 +180,7 @@ char *lastpart(char *path)
     return path;
 }
 
-msg_mclass_t *mclass = NULL;
+msg_mclass_t const *mclass = NULL;
 
 int validate_file(int fd, char const *name, context_t *ctx);
 int validate_dump(char *, off_t, context_t *ctx);