use default if request port is 0.

lichao

2021-06-01 7c8e2433992aac41bdeb0d7d0861b738d9866628

use default if request port is 0.

 box/center.cpp

@@ -104,7 +104,11 @@
                            center->PassRemoteReplyToLocal(dest, head, std::move(body_content));
                        }
                    };
                    if (!tcp_proxy.Request(head.dest().ip(), head.dest().port(), msg.content(), onResult)) {
                    uint16_t port = head.dest().port();
                    if (port == 0) {
                        port = kBHCenterPort;
                    }
                    if (!tcp_proxy.Request(head.dest().ip(), port, msg.content(), onResult)) {
                        replyer(MakeReply<Reply>(eError, "send request failed."));
                    } else {
                        // success