Bug 33362: Allow return claims to be resolved even if the issue has since been delete...

Bug 33362: Allow return claims to be resolved even if the issue has since been delete from the database

Test Plan:
1) Check out an item
2) Claim return on it, moving it to the old_issues table
3) Delete the old_issue via koha-mysql or Use cleanup_database.pl
4) Attempt to resolve the claim
5) Note the error
6) Apply this patch set
7) Restart all the things!
8) Attempt to resolve the claim
9) No errors!

Signed-off-by: Sam Lau <samalau@gmail.com>
Signed-off-by: Victor Grousset/tuxayo <victor@tuxayo.net>
Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>