Disable check for all minions returned when using syndic

This optimisation meant that if all minions targeted were connected to
syndics, rather than directly we would never look for events
Don't risk missing events in gather_job_info

Seen with syndic, but in theory affects all setups. When a we call
gather_job_info if an event comes in for the main job we can discard the
event whilst we are looking for the gather_job_info event. To work
around I've made gather_job_info add events for the main job to the
pending_events list. get_event now always checks that list for events
matching it's tag