Bug 10311 - Holds queue ignores item-level holds where only one items exists

If a record has only one item, and that item has one item-level hold on
it, that hold will not show in the holds queue.

Test Plan:
1) Create 1 record with 1 item at BranchA
2) Create an item-level hold for that item, for pickup at BranchA by a
   patron of BranchA
3) Run build_holds_queue.pl
4) View the holds queue for BranchA
5) Note the hold is not in there
6) Apply this patch
7) Re-run build_holds_queue.pl
8) View the holds queue again
9) Not that the hold is now there

Signed-off-by: George Williams <georgew@latahlibrary.org>
Signed-off-by: Chris Cormack <chris@bigballofwax.co.nz>
Signed-off-by: Galen Charlton <gmc@esilibrary.com>