Restore command cannot drop postgres database

[JAForbes]

Because it connect to the cluster URL, postgres defaults to the default database, if the default database is also the users application database that they restore into then the command will fail.

Probably should just document we recommend/require having a non default db for restore, which is best practice anyway.

But we could also create some temp db, connect to that, drop postgres and restore it I suppose. But I think we should only go down that route if there's a need.