message: fix dispatch_func bug
diff: @@ -405,7 +405,7 @@ int php_swoole_dispatch_func(swServer *serv, swConnection *conn, swEventData *da
  ZVAL_STRINGL(zdata, data->data, data->info.len);
  SW_MAKE_STD_ZVAL(zfd);
  - ZVAL_LONG(zfd, (long ) conn->session_id);
  + ZVAL_LONG(zfd, (long) conn ? conn->session_id : data->info.fd);
  SW_MAKE_STD_ZVAL(ztype);
  ZVAL_LONG(ztype, (long) data->info.type);
  