Bug 30966: Record Overlay Rules - can't use Z39.50 filter

Bug 30966: Record Overlay Rules - can't use Z39.50 filter

This patch fixes overlay rules on z39.50 import

Test plan:
1) Create protection overlay rule to some fields for z39.50.
2) Import a record via z39.50.
3) See that the protected fields are replaced on the editor.
4) Apply the patch.
5) Import a record again.
6) See that the protected fields are in place on the editor.

Sponsored-by: Koha-Suomi Oy
Signed-off-by: Michaela Sieber <michaela.sieber@kit.edu>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
(cherry picked from commit 0970eef56df1ac8fee1f3c5f0216a164be5048ec)
Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>