Bug 37192: Adjust template for additem.tt

Bug 37192: Adjust template for additem.tt

Test plan:
1. Search the catalog for something that will return results, like Perl
2. On any bib that has at least one item, click Edit items
3. In the Actions menu to the left of any item, choose Print label
4. That opened a popup with a 500 error rather than a label batch editor
5. Apply patch, restart_all
6. Repeat step 3, but this time you'll get a label batch editor with your
   item in it.

Signed-off-by: Phil Ringnalda <phil@chetcolibrary.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Katrin Fischer <katrin.fischer@bsz-bw.de>