bibdocfile: fix cli_set_batch function
bibdocfile: fix cli_set_batch function

* Properly gather description, comment and restriction arguments
  in cli_set_batch in order to be able to set one of the above
  without erasing the others.

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