Bug 24507: Make Checkouts/ReturnClaim.t pass on MySQL 8

Bug 24507: Make Checkouts/ReturnClaim.t pass on MySQL 8

 $ prove t/db_dependent/Koha/Checkouts/ReturnClaim.t
 t/db_dependent/Koha/Checkouts/ReturnClaim.t ..
     #   Failed test 'Exception field is correct'
     #   at t/db_dependent/Koha/Checkouts/ReturnClaim.t line 97.
     #          got: 'return_claims.issue_id'
     #     expected: 'issue_id'
     # Looks like you failed 1 test of 8.
 t/db_dependent/Koha/Checkouts/ReturnClaim.t .. 1/1
 #   Failed test 'store() tests'
 #   at t/db_dependent/Koha/Checkouts/ReturnClaim.t line 133.

This is similar to bug 23825.

Test plan:
Confirm that the tests pass on MySQL8 and MariaDB

Signed-off-by: Tomás Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Martin Renvoize <martin.renvoize@ptfs-europe.com>