Fix over-application bug of EM_COINC
This is a rather serious bug that was created by an oversight in !560 (merged) where EM_COINC
is being applied to every superevent regardless of the RAVEN search. This fixes it by putting the application of this label within the raven results loop.
See Sentry Error: https://sentry.io/organizations/ligo-caltech/issues/1126202298/events/?environment=playground
See playground query: https://gracedb-playground.ligo.org/search/?query=&query_type=S&results_format=S