vars changes in question are from commit: 8b94bc71bc
With this changeset the age specific sops logic that was added is now
generic.
To keep things simple, this changeset modifies `SopsKey` so that
`username` is ignored when comparing different keys. I don't really see
us relying on `username` and this makes `SopsKey` hashable, and usable
in a `set`, which is nice when you check that you have a particular key.
07cd22393a