Bug 14966: Table header broken at detail.tt

Bug 14966: Table header broken at detail.tt

For user without item edit permission, table at catalogue/detail.pl is
corrupted.

Test plan:
1) Log in as staff member, without edit item permission.
2) Go to biblio view, with items attached:
/cgi-bin/koha/catalogue/detail.pl?biblionumber=X. Confirm that table
does not display correctly.
3) Apply patch.
4) Repeat steps 1 and 2. Confirm patch works.

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>

Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>