bugfix(lan): Always allow players to join a LAN room if there is an open slot

[Stubbjax]

This change fixes an issue where players cannot join a LAN room if the current player count, minus any observers, is greater than or equal to the number of player spawn positions on the selected map. The selected map should have no influence on whether players can join the room.

Example 1: A room with a 2-player map and 2 players has a 3rd open slot - nobody can join unless one of the players is an observer.

Example 2: A room with a 6-player map and 6 players has a 7th and 8th open slot - a 7th player cannot join unless one player is an observer, and an 8th player cannot join unless two players are an observer.

[xezon]

Nice.

Can add a comment above the function that highlights that players can now join open slots regardless of starting spots on the map.

[Mauller]

Have you tested what affect this has if you start a game with more players in the lobby than spots on the map?

[Stubbjax]

Have you tested what affect this has if you start a game with more players in the lobby than spots on the map?

The game won't let you start a match if there are more (non-observer) players in the room than map positions.