Bug 19835: Fix repeatability on MARC21 subfields

Bug 19835: Fix repeatability on MARC21 subfields

This followup fixes all repeatability cases, from
updates 23+24+25 and a few older ones.

To test:
0) Apply both patches
1) Remove all your frameworks
2) Check mandatory bibliographic and authority files load without problem
3) Check repeatability...

Bibs and auth frameworks checked against LOC description.

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Josef Moravec <josef.moravec@gmail.com>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
(cherry picked from commit c1f916c1aa6e4937eca2dcf5b6493368d18cbcae)
Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>