fix-redis-response-swap-mem-leak

[qqwangxiaow]

What problem does this PR solve?

redis response swap operation may cause memory leaks
Issue Number:

Problem Summary:
redis reply _arena address should be the same as respone, otherwise, there may be a memory leak.

test code

    brpc::RedisResponse resp1;
    std::cout << "response 1 arena address:"<< &(resp1._arena) << std::endl;
    std::cout << "first reply arena address:" << (resp1._first_reply._arena) << std::endl;
    brpc::RedisResponse resp2;
    std::cout << "response 2 arena address:"<< &(resp2._arena) << std::endl;
    std::cout << "first reply arena address:" << (resp2._first_reply._arena) << std::endl;

    resp1.Swap(&resp2);
    std::cout << "========= swap ============" << std::endl;
    std::cout << "response 1 arena address:"<< &(resp1._arena) << std::endl;
    std::cout << "first reply arena address:" << (resp1._first_reply._arena) << std::endl;;
    std::cout << "response 2 arena address:"<< &(resp2._arena) << std::endl;
    std::cout << "first reply arena address:" << (resp2._first_reply._arena) << std::endl;

bug version

fixed version

What is changed and the side effects?

Changed:

Side effects:

• Performance effects(性能影响):
  no
• Breaking backward compatibility(向后兼容性):
  no

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Check List:

• Please make sure your changes are compilable(请确保你的更改可以通过编译).
• When providing us with a new feature, it is best to add related tests(如果你向我们增加一个新的功能, 请添加相关测试).
• Please follow Contributor Covenant Code of Conduct.(请遵循贡献者准则).

[serverglen]

LGTM

[heartplus]

nobody except RedisRespone.Swap calls RedisReply.Swap, so it is safety to change behaviour of RedisReply.Swap
// i just renamed RedisReply.Swap to RedisReply.Swap2 to check whether compile passed or not

[chenBright]

LGTM