Revert "Bug 28510: Remove unnecessary conditional"

Revert "Bug 28510: Remove unnecessary conditional"

This reverts commit d284735d05f67226feba1b4b9e7bf17259eaabaf.

The following test was failing randomly:
 #   Failed test 'take from lowest cost branch (don't use cost matrix) holding branch'
 #   at t/db_dependent/HoldsQueue.t line 1494.
 #          got: 'LHKtxLk'
 #     expected: 'JL9C_OR'
 # Wrong pick-up/hold for first target (pick_branch, hold_branch, reserves, hold_fill_targets, tmp_holdsqueue)

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