[PR] Make NTSO only available if a HoS has joined the round

[Drago156]

Yea I'm not personally in favor of this. HoS and NTSO do play quite differently and have different levels of stress and expectations attached to them. Late joining as HoS isn't always the best experience over simply joining in as NTSO. I'd like to also present a major issue this would create with a specific game mode: Revs. As it stands, you can't latejoin as any Head of Staff position on a rev round, which would effectively completely disable NTSO if a HoS wasn't present at the start of a rev round.