Called when a player attempts to spawn via class selection either by pressing SHIFT or clicking the 'Spawn' button.
|playerid||The ID of the player that requested to spawn.|
It is always called first in filterscripts so returning 0 there also blocks other scripts from seeing it.
This callback can also be called by NPC.
To prevent players from spawning with certain classes, the last viewed class must be saved in a variable in OnPlayerRequestClass.