elasticsearch: fix for signal receivers arguments
elasticsearch: fix for signal receivers arguments

* Adds keyword arguments to signal receivers.  (PR #2594)

Acked-by: Jiri Kuncar <2bdffcb416fed3002465740d19a053a39918cbe5@cern.ch>
Signed-off-by: Johnny Mariéthoz <850644a4434c532c9fdce77a032c0d2d610780c4@rero.ch>

tiborsimko/invenio,inveniosoftware/invenio,inveniosoftware/invenio,tiborsimko/invenio