Change the datanode MySQL default port

[killme2008]

What type of enhancement is this?

Configuration

What does the enhancement do?

Right now the datanode listens on 127.0.0.1:3306 for MySQL connections, it may conflict with the user's MySQL server, so we should change this default address.

Implementation challenges

No response

[azhsmesos]

Please assigned it to me

[waynexia]

Closed by https://github.com/GreptimeTeam/greptimedb/pull/568