fix: no need to close the connection that is closing

[bytemain]

ref: pladaria#197

[titanism]

This will still throw an error if it is in a CONNECTING state.

See https://github.com/websockets/ws/blob/0d1b5e6c4acad16a6b1a1904426eb266a5ba2f72/lib/websocket.js#L290-L294

[bytemain]

Seems a little confusing to me, I think we actually did need to close the CONNECTING connection.

I think the error you say maybe happened on we close a CLOSING socket instead of a CONNECTING socket.

we can see the ws code, when we close the CONNECTING connection, the ws package will change its state to CLOSING, emit error and close event in the next tick.

for code in the master branch, when it receive error event, it will invoke _disconnect to close the original ws connection, but here the connection is already CLOSING or CLOSED, it may raise an error.

[bytemain]

And I cannot understand why the process will exit, I will try to reproduce it.