[RoomInviter] 已在房间，但还继续发送welcome消息

[fangmuke]

假如某个用户已经在某个房间时，该用户再次向bot发出加入请求，这时bot会发送welcome消息，然后才处理repeat。

代码位于https://github.com/wechaty/wechaty-plugin-contrib/blob/fb4b3774d0c34833e0cf2a876e922fa7242b8248/src/contrib/room-inviter.ts#L47

[huan]

Thanks for creating this issue.

Could you please explain what is the behavior that you expected?

And a PR would be welcome.