Bug 20777: (follow-up) Remove 'dispute' reference in /credits endpoint

Signed-off-by: Tomas Cohen Arazi <tomascohen@theke.io>

Signed-off-by: Mark Tompsett <mtompset@hotmail.com>

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

Signed-off-by: Nick Clemens <nick@bywatersolutions.com>

Koha/REST/V1/Patrons/Account.pm

@@ -228,7 +228,6 @@ our $to_api_mapping = {
     accounttype       => 'account_type',
     amountoutstanding => 'amount_outstanding',
     borrowernumber    => 'patron_id',
-    dispute           => undef,
     issue_id          => 'checkout_id',
     itemnumber        => 'item_id',
     manager_id        => 'user_id',