Bug 14450: itemsearch no longer working

Bug 14450: itemsearch no longer working

To test:
Click Advanced search in staff client
Click the link for "Go to Item Search" at the top of the page
Do a search, you should get results. Try some combinations and make sure it works like it should.

Signed-off-by: Jacek Ablewicz <abl@biblos.pk.edu.pl>
Signed-off-by: Jonathan Druart <jonathan.druart@koha-community.org>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit f900ea03bf15746bd2c310b59f2fb06972f6bdee)
Signed-off-by: Chris Cormack <chrisc@catalyst.net.nz>