Bug 32830: Fix cataloguing/value_builder/unimarc_field_116.pl

Bug 32830: Fix cataloguing/value_builder/unimarc_field_116.pl

Use event parameter

This is part of the refactoring happening in bug 30975

Test plan:
1. Verify that the plugin continues to work as before

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>
https://bugs.koha-community.org/show_bug.cgi?id=32831
(cherry picked from commit 4d196b176d6cfb258e9c729116db377cf5e17fd1)
Signed-off-by: Matt Blenkinsop <matt.blenkinsop@ptfs-europe.com>