Bugfix: Clients were not removed from channels on disconnect

On disconnect, sockets are in no rooms anymore - even before kicking them out manually.
Because of that, removeClient() did cancel in beginning...
But anaway, we have to remove the client from the unique users list - so force it.

src_coffee/server/channel.coffee

@@ -138,7 +138,8 @@ class Channel
         return true
     removeClient: (clientSocket, isClose=false, isDisconnect=false) ->
-        return false unless clientSocket.rooms.indexOf(@name) >= 0  # Cancel, if socket is not joined to channel
+        # Cancel, if socket is not joined to channel (but force on disconnect)
+        return false if not isDisconnect and clientSocket.rooms.indexOf(@name) < 0
         log.debug "Removing client #{clientSocket.identity.getName()} from channel '#{@name}' (by close: #{isClose})"