handle_grb_lvalert redundencies
Looking at the worker logs, handle_grb_lvalert is being called for two keys, 'external_fermi' and 'external_fermi_grb', where these can both be called very close in time (see gwcelery-worker-log__1_.txt). At least two calls go through much of the external_trigger.py/raven.py logic until one tries to add the external trigger first, prompting an error for the other once it got that far. This would occur here (https://git.ligo.org/emfollow/gwcelery/blob/master/gwcelery/tasks/raven.py#L114
and leads to the error:
Because of this two RAVEN searches are performed and uploaded as well. Examples of these double calls for RAVEN are ubiquitous but here's an example for one of the events with the error above: https://gracedb-playground.ligo.org/events/E22402/view/
A solution would be simply to disable one of these keys. Keeping 'external_fermi' would put fermi in line with swift which has key 'external_swift'.