[Feature] [Minor] Brig flusher tweak

[Firebarrage]

People constantly get stuck in the brig and end up permabrigged over a 1 minute sentence. This is because brig flushers shut themselves after 30 seconds, for some odd reason. This patch just removes that timer and makes them stay open until someone falls in.



Short and sweet patch.
https://github.com/goonstation/goonstation-2016/pull/37