BibCatalog: no newlines in subject for RT plugin
BibCatalog: no newlines in subject for RT plugin

* Properly cleans any newlines from the given subject for the
  RT plugin as newlines are not accepted by the CLI bridge to RT.

Signed-off-by: Jan Aage Lavik <8d55e006a1b29770f275a5c59a7341f17f8e69d5@cern.ch>
Reviewed-by: Samuele Kaplun <2e218f779e12714c314fad8ebf6b3041daa21337@cern.ch>

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