bug 2317: avoid crash when auto-creating authority

bug 2317: avoid crash when auto-creating authority

If BiblioAddsAuthorities is ON, saving a MARC bib record
in the cataloging editor can create new authority records.
When using MARC21, if one of those authority records
has diacritics in its heading, the save crashes with the
following error:

Wide character in null operation at
/usr/local/share/perl/5.8.8/MARC/Charset/Table.pm line 96

To prevent this, new MARC21 authorities created by
BiblioAddsAuthorities have the Leader/09 set to 'a'.  Note
that this is not currently required for UNIMARC authorities,
as MARC::File::XML->as_xml_record() does not attempt
to transcode UNIMARC records from MARC-8 to UTF-8.

Signed-off-by: Joshua Ferraro <jmf@liblime.com>