Bug 19009: Fix random failures from Circulation.t

Bug 19009: Fix random failures from Circulation.t

From jenkins output:
 Subtest: CanBookBeIssued + Koha::Patron->is_debarred<7c>has_overdues
1..8
not ok 1
[SKIP]

I executed it several times and display the different $error, $alerts and question keys.
GNA and RESTRICTED were sometimes set, which block the issue.
Reading the code it seems that some patron's attributes must be removed to avoid the checkin rejection.

Test plan:
Execute the tests several times and notice that it fails randomly
With this patch they should always pass.

Signed-off-by: Owen Leonard <oleonard@myacpl.org>
Signed-off-by: Marcel de Rooy <m.de.rooy@rijksmuseum.nl>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>