api2/config/tape_backup_job: fix duplicate id parameter

api2/config/tape_backup_job: fix duplicate id parameter

since the PUT api call is using the 'Updater', the 'id' parameter is
already encoded in there, tripping up the api verify tests with
'Duplicate keys found in AllOf schema: id'

"fixing" it by removing the explicit id from the api call and
taking it from the Updater (and failing if it does not exists there;
even though that should never happen)

Signed-off-by: Dominik Csapak <d.csapak@proxmox.com>