Remove traitor PDAs from revolution rounds

[Winklabom]

In my experience, rev heads silently convert tons of people and then just wander the station in packs to beat the crap out of any head of staff they encounter.

I don't actually know if the rev heads can only use their starter flash to convert people, but even then a single flash can be used 5 or 6 times whereas a mind slave or a loyalty can only be used once.

3 rev heads flashing 5 people each means that almost the entire crew is a revolutionary within the first 10 minutes of the shift.

I don't think they should be given a way to order additional flashes.