Workaround for pusherver/bridge disconnect problems has side effects on bots

[frandallfarmer]

The bridge change that works-around shutting down the bridge on pushserver port closes has a side effect: Bots don't exit when disconnected. This means that they won't restart when some things go wrong.

[kevzettler]

apparently related to https://github.com/frandallfarmer/neohabitat/issues/393