lobby_threshold is applied to active players on the server even if they don't have a TS mapping or are not currently on the TS Server

[FrederikP]

Example:
If lobby_threshold is set to 4, and there are at least 4 players are active on the csgo server, the plugin will move players to the defined channels even when less than 4 players are actively connected to the TS server and available in the mappings.

Expected:
lobby_threshold should apply to the number of active players that are actually online in TS and have a mapping