message: fix connection_iterator crash
diff: @@ -2007,6 +2007,7 @@ PHP_METHOD(swoole_server, __construct)
  swConnectionIterator *i = emalloc(sizeof(swConnectionIterator));
  bzero(i, sizeof(swConnectionIterator));
  + i->serv = serv;
  swoole_set_object(connection_iterator_object, i);
  #endif
  