BibFormat: formatting of not-yet-existing records
BibFormat: formatting of not-yet-existing records

* Do not fail when formatting records that do not exist yet.
  (cherry-picked from 4f2faee5e1b10e1f9a7279612ff1bbb22bb6b00d)

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