The import-mbox script --dry option no longer works unless an ES database is available.
This is because Elastic() now checks the database version during init. Whilst it is a good idea to check the version, it seems wrong to do it in the init function. Either the check needs to be moved, or the scripts need to avoid initialising Elastic in dry-run mode. Also archiver.py now does the same check as Elastic init, which is redundant.
