Fix cs_set_user_team issue on spectator

Bug reported by ^SmileY here : https://forums.alliedmods.net/showthread.php?t=240079.

Issue happens when ```cs_set_user_team``` is used with ```CS_TEAM_SPECTATOR``` wherein native is supposed to tell core about this team change and for some reason it was missing for spectator, resulting others natives using old team data.