Added 404 error when DIP-related data not found in DB.
Added 404 error when DIP-related data not found in DB.

eckardm/archivematica,eckardm/archivematica,artefactual/archivematica,sevein/archivematica,michal-ruzicka/archivematica,michal-ruzicka/archivematica,sevein/archivematica,artefactual/archivematica,artefactual/archivematica,michal-ruzicka/archivematica,artefactual/archivematica,eckardm/archivematica,eckardm/archivematica,sevein/archivematica,sevein/archivematica,michal-ruzicka/archivematica