fs-mistrust: Actually encode and decode OsString usernames
It turns out that the toml
crate can't handle OsString, since
toml
doesn't support serialize_newtype_variant, and the serde
crate tries to serialize OsString using that method.
Found by inspecting test coverage.
It is possible that this whole MR is a mistake and we should just forbid non-UTF8 usernames in our toml?