**Describe the bug**
ClickHouse doesn't return affected rows via MySQL protocol for INSERT queries after 20.5+

**How to reproduce**
i create clear docker-compose environment for reproduce behavior MySQL + clickhouse + php + python
https://gist.github.com/Slach/aa67440ce856a3a53f64f92eeddfbc1b

**Queries to run that lead to unexpected result**
```
INSERT INTO default.t1(n) SELECT * FROM numbers(1000)
```

**Expected behavior**
MySQL protocol shall return affected rows field for INSERT queries (it works successful in 20.3 and 20.4)
![image](https://user-images.githubusercontent.com/105560/97867431-aa22ae00-1d2f-11eb-8caf-05431ffd29b3.png)

**Actual behavior**
![image](https://user-images.githubusercontent.com/105560/97867401-9f681900-1d2f-11eb-93cc-5ae6f1f5981b.png)
{
                should_replace = true;
                replacement_query = x.second(query);
                break;
            }
        }
        ReadBufferFromString replacement(replacement_query);
        Context query_context = connection_context;
        executeQuery(should_replace ? replacement : payload, *out, true, query_context,
            [&with_output](const String &, const String &, const String &, const String &)
            {
                with_output = true;
            }
        );
        if (!with_output)
            packet_endpoint->sendPacket(OKPacket(0x00, client_capability_flags, 0, 0, 0), true);
    }
}
void MySQLHandler::authPluginSSL()
{
    throw Exception("ClickHouse was built without SSL support. Try specifying password using double SHA1 in users.xml.", ErrorCodes::SUPPORT_IS_DISABLED);
}
void MySQLHandler::finishHandshakeSSL(
    [[maybe_unused]] size_t packet_size, [[maybe_unused]] char * buf, [[maybe_unused]] size_t pos,
    [[maybe_unused]] std::function<void(size_t)> read_bytes, [[maybe_unused]] MySQLProtocol::ConnectionPhase::HandshakeResponse & packet)
{
    throw Exception("Client requested SSL, while it is disabled.", ErrorCodes::SUPPORT_IS_DISABLED);
}
#if USE_SSL
MySQLHandlerSSL::MySQLHandlerSSL(IServer & server_, const Poco::Net::StreamSocket & socket_, bool ssl_enabled, size_t connection_id_, RSA & public_key_, RSA & private_key_)