Bug 28496: Club holds pickup locations don't come from the API

Bug 28496: Club holds pickup locations don't come from the API

This patch fixes a issue that is generated by the fact different inputs
were reusing the same id.

To test:
1. Have a club with some enrollments
2. Make sure you have your circ rules to allow any  library be a pickup
   location.
3. Search for a biblio
4. Try placing a club hold
=> FAIL: The dropdown only has the (currently) logged in library.
5. Apply this patch
6. Repeat 3-4
=> SUCCESS: The dropdown has all the options

Signed-off-by: David Nind <david@davidnind.com>
Signed-off-by: Katrin Fischer <katrin.fischer.83@web.de>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>