BibField: fix for '__eq__' to better compare recs
BibField: fix for '__eq__' to better compare recs

Signed-off-by: Esteban J. G. Gabancho <03cb568148df368b792a31d9c4d06b12dc802700@cern.ch>
Tested-by: Tibor Simko <c7116e45300b163846dc01f3ed02116e3f8ef7a5@cern.ch>

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