Fix humanoid empty action queue

This fixes the problem reported in #306.

When the tickDay function sends a patient to the toilets, there is a small timeframe (the time required for standing up), where the tryToFindNearbyPatients function tries to reroute a patient who is going to the toilet.

This will set the seek_toilets todo_interrupt and the finishAction function is then called one time too often by the seek_toilets action itself and all actions from the action queue are consumed, so the error message pops up.