Bug 34029: (QA follow-up) Fix pushing undef to biblio_ids

Bug 34029: (QA follow-up) Fix pushing undef to biblio_ids

See comment1. Although we now fix the error on publishercode, it
is good to verify the result before pushing.

Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 377e2a70dec073063443c23e9b6a06f54da6b53c)
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit 561f6e5bd8dc5c9a671168fde67d412dbe3a0895)
Signed-off-by: Pedro Amorim <pedro.amorim@ptfs-europe.com>