The user loading code is kind of convoluted: it loads all the separate
backend items from the `/web/users/` prefix into a struct. That struct
is then converted to a full `types.User` object.
For each user there are 3 kinds of backend items:
- `/params` which is the main one, containing a marshalled `types.User`
object
- `/pwd` which contains the hashed password for local users
- `/mfa/...` which contain registered MFA devices
When an SSO user expires, we delete the first two items but not
`/mfa/...`. This is intentional, to persist MFA devices across logins.
The user loading code would fail because the user was "found" (thanks to
MFA items), but didn't have the mandatory `/params` item.
This PR ignores any users that don't have `/params` instead of
hard-failing all `GetUsers` calls.
Andrew Lytvynov
3cfdc9b6f7