Fixes a potential "fail to setup jobs" state due to disappearing clients (#64735)
Fixes a potential "fail to setup jobs" state due to disappearing clients (#64735)

Fixes a runtime error that can occur during DivideOccupations() in the event that one of the players has their clients disappear during setup due to classic byond client volatility.

If a new player's client vanishes during job setup, it will read as null instead of runtiming, which throws a JobDebug and moves onto the next player.
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