Kick after opening a LAN lobby shortly after closing a LAN game.

[Wirox]

Steps to reproduce:

1. Launch OCTGN and either do not sign in or remember to enable "Host Game on LAN" before opening lobbies in points 2 and 4.
2. Open a lobby and start the game.
3. Close the game.
4. Quickly open a lobby again (less than ~25 seconds need to pass before the new lobby opens).
5. Observe a message saying
   You have been kicked: This game is already started and is no longer accepting new players.
You have been disconnected from server.
   or
   You have been disconnected from server.
   If you try to start this game, you'll be disconnected without the possibility of reconnecting.

This issue is especially problematic when testing, which often involves repeatedly starting games.

[brine]

I believe this is related to a timeout being triggered on the standalone server, it doesn't shut down right away. Might need to have some sort of shutdown notification to tell the server its safe to shut down.