message: support dns server port option.
diff: @@ -369,13 +369,23 @@ int swDNSResolver_request(char *domain, void (*callback)(char *, swDNSResolver_r
  sw_free(request);
  return SW_ERR;
  }
  - if (resolver_socket->connect(resolver_socket, SwooleG.dns_server_v4, SW_DNS_SERVER_PORT, 1, 0) < 0)
  + char *_port;
  + int dns_server_port = SW_DNS_SERVER_PORT;
  + char dns_server_host[32];
  + strcpy(dns_server_host, SwooleG.dns_server_v4);
  + if ((_port = strchr(SwooleG.dns_server_v4, ':')))
  + {
  + dns_server_port = atoi(_port + 1);
  + dns_server_host[_port - SwooleG.dns_server_v4] = '\0';
  + }
  + if (resolver_socket->connect(resolver_socket, dns_server_host, dns_server_port, 1, 0) < 0)
  {
  do_close: resolver_socket->close(resolver_socket);
  swClient_free(resolver_socket);
  sw_free(resolver_socket);
  sw_free(request->domain);
  sw_free(request);
  + resolver_socket = NULL;
  return SW_ERR;
  }
  SwooleG.main_reactor->setHandle(SwooleG.main_reactor, SW_FD_DNS_RESOLVER, swDNSResolver_onReceive);
  