Close the connection to another system.
Connection index defines which system to close the connection to (from the Network connections array).
You can define the connection to close via Guid if the index is unknown.
If we are a client the only possible connection to close is the server connection, if we are a server the target player will be kicked off.
Send Disconnection Notification enables or disables notifications being sent to the other end. If disabled the connection is dropped, if not a disconnect notification is reliably sent to the remote party and there after the connection is dropped.