deposit: fix fields argument on post processors

• Updates sherpa romeo methods to receive fields argument.

Signed-off-by: Pedro Gaudêncio <pedro.gaudencio@cern.ch>
Reviewed-by: Javier Martin Montull <javier.martin.montull@cern.ch>
Reviewed-by: Lars Holm Nielsen <lars.holm.nielsen@cern.ch>
Reviewed-by: Jiri Kuncar <jiri.kuncar@cern.ch>