add kick-when-online configuration option

[lipind]

Is your feature request related to a problem? Please describe.

Multiple proxy players can use two accounts (with the same name) to access the server simultaneously, which may cause some bugs,

I thought it was harmless before

But yesterday, on my server, the player accessed both Aproxy-Cserver and Bproxy-Cserver simultaneously

When a player is kicked out It has reached a state of "invisibility", which I analyze to be related to packet sending errors

Can you add a kick when online option？
I think this is missing from ConnectorPlugin

Describe the solution you'd like

When player tries to join with the same account "from another location" (using another computer or even another game window), he cannot join the server, and the client that is already connected to the server remains not kicked.

kick-when-online = false（I think this is similar to the logic of RedisBungee and more convenient for the public）

Describe alternatives you've considered

There can only be one player (with the same name) on a proxy's server
like ABCDserver in A-proxy,EFGHservver in B-proxy.
ABCDserver only be one player (with the same name)
Newly joined players(with the same name) will be kicked out

Additional context

Online mode players can also exploit this bug

[Folas1337]

I highly recommend using this instead: https://github.com/ProxioDev/ValioBungee

ConnectorPlugin seems like the wrong plugin to take care of such a thing.

[Phoenix616]

ConnectorPlugin seems like the wrong plugin to take care of such a thing.

While you are right that this isn't the best plugin which should handle such things the described case could actually cause issues in how the plugin works itself (as you can send messages to a server/proxy where a specific player is connected to. Duplicate players would make this weird). Besides the fact that there is the precedence of the bridge adding functionality beyond just acting as a library already so I will think about what the best approach here is.