accommodate PL/pgSQL that logs deletes

`_fs_deletelog()` makes brittle assumptions about table column ordering. To test, make sure that you can delete images from a 4.4 → 5.0 upgraded DB (upgrade using `sql/psql/OMERO5.0DEV__6/OMERO4.4__0.sql`). After upgrade delete images that were imported both before and after upgrade.

--no-rebase as is FS model specific.