DB privilege error: poimport on TranslationMessage

Just saw a permission-denied error from the translations importer, on TranslationMessage: http://paste.ubuntu.com/713107/

That may seem surprising, since the importer already has SELECT / INSERT / UPDATE on that table. But it makes sense. With translations message sharing, in rare cases, we may have to delete translation messages. We never thought to grant the DELETE privilege though, because it's so rarely needed and we don't normally delete data from this table.

When would we need to delete a TranslationMessage? When a current, diverged TM converges, but can't be updated because there's already an identical non-diverged message in the way. It may have happened before, but the appserver has all the privileges it needs.