WebUI: Fix error "unknown command 'idoverrideuser_add_member'"

There was wrong IPA.associator class used for 'Groups' -> 'User ID overrides' association,
as a result a wrong command was sent to the server.

Ticket: https://pagure.io/freeipa/issue/8416

Signed-off-by: Serhii Tsymbaliuk <stsymbal@redhat.com>
Reviewed-By: Petr Vobornik <pvoborni@redhat.com>
Reviewed-By: Alexander Bokovoy <abokovoy@redhat.com>

install/ui/src/freeipa/group.js

@@ -209,7 +209,6 @@ return {
         {
             $type: 'association',
             name: 'member_idoverrideuser',
-            associator: IPA.serial_associator,
             add_title: '@i18n:objects.group.add_idoverride_user',
             remove_title: '@i18n:objects.group.remove_idoverride_users',
             columns: [