Bug 27731: Remove hold class from individual OPAC search result hold link

Bug 27731: Remove hold class from individual OPAC search result hold link

This patch removes the "hold" class from the "Place hold" link
associated with each search result in the OPAC. The class isn't required
for any functionality or style and it unintentionally triggers the "hold
multiple" JS function which requires that a checkbox be checked.

To test, apply the patch and log into the OPAC as a user who can place
holds.

- Perform a catalog search which will return multiple results.
- Click the "Place hold" link under any search result.
- You should be taken to the hold confirmation page.
- On the search results page, confirm that the "Place hold" link at the
  top of the search results still works to place multiple holds at once.

Signed-off-by: Phil Ringnalda <phil@chetcolibrary.org>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>