SCServerSocket.kickOut doesn't modify `channelSubscriptions`

[Aareksio]

https://github.com/SocketCluster/socketcluster-server/blob/master/scserversocket.js#L498

SCServerSocket.kickOut doesn't modify channelSubscriptions list making calling SCServerSocket.subscriptions return a list including channels the client is no longer subscribed to.

Moreover, it doesn't affect SCServerSocket.channelSubscriptionsCount, which may eventually lead to exceeding SCServer.socketChannelLimit.

[jondubois]

@Aareksio Thanks for raising this issue. It's been fixed in socketcluster-server v14.2.1.