[dataimport] remove replace_sep parameter from massive store
It is unused since changeset efbbf1e93a04 "[dataimport] Properly escape
strings sent to COPY FROM"
sync_schema_props_perms('cwuri')
helper = repo.system_source.dbhelper
cu = session.cnxset.cu
helper.set_null_allowed(cu, 'moved_entities', 'extid', 'VARCHAR(256)', False)
commit()