Added timeout non-zero verification - fixes #776

The pubsub listener was making the `bstop` call wait forever, because it was never listening in the first place: the 0 second `Duration` timeout was being triggered, rather than being considered as a "no timeout" value.
It's not very relevant for performance, I was trying to figure out where all those timers came from when tracing and afterwards, I realized it would have been easier to debug it if it showed up as the same ID.