Comment 2 for bug 1726317

The actual fix for them was to force the space with "mongo-space-name". Which we should make sure we can do after the fact.
Unfortunately we can't really block "juju enable-ha" if we want to use auto-detection, because the other machines won't be up for us to know how to auto-detect. Otherwise we could do something like "you must set mongo-space-name before you can enable-ha".