Bug 30769: Typo fix in request.tt

Bug 30769: Typo fix in request.tt

This patch fixes a small typo at
koha-tmpl/intranet-tmpl/prog/en/modules/reserve/request.tt:574

To test:
1 - Set item-level_itypes in administrative preferences to
    bibliographic record
2 - Navigate to /reserve/request.pl in admin interface
3 - Notice that the typo is there in hold details
4 - Apply Patch
5 - Typo is fixed

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>