Bug 23970: Make search with "Publication date" field work at any position

Bug 23970: Make search with "Publication date" field work at any position

The changes made in the following commit:
  commit 0d2e83bca5b91376e9262b6cb0b993f09b919018
  Bug 14636: Item search - fix search and sort by publication date for MARC21
was put at the wrong place. It was inside a "if $i == 1" test that
impacts the first field only.

Test plan:
0/ Use a MARC21 installation
1/ Search items by publication date, use twice the field using different
values.
For instance:
  publication date: 2005 OR
  publication date: 2006
=> Without this patch you only get results for 2005
=> With this patch applied you get results for both years.

Signed-off-by: Joonas Kylmälä <joonas.kylmala@helsinki.fi>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>