Override #compute_amount in ReturnAuthorization
Override #compute_amount in ReturnAuthorization

In some cases adjustments are updated (recalculated) via their originator. In the case of return adjustments, there's no calculation (and no calculator).

mkllnk/openfoodnetwork,lin-d-hop/openfoodnetwork,lin-d-hop/openfoodnetwork,mkllnk/openfoodnetwork,openfoodfoundation/openfoodnetwork,Matt-Yorkley/openfoodnetwork,openfoodfoundation/openfoodnetwork,Matt-Yorkley/openfoodnetwork,openfoodfoundation/openfoodnetwork,lin-d-hop/openfoodnetwork,lin-d-hop/openfoodnetwork,mkllnk/openfoodnetwork,Matt-Yorkley/openfoodnetwork,mkllnk/openfoodnetwork,Matt-Yorkley/openfoodnetwork,openfoodfoundation/openfoodnetwork