Encode/decode rountrip error with `UcanResource::OwnedBy`

[matheus23]

This test case fails:

#[test]
fn test_broken_ucan() -> Result<()> {
    let issuer = &EdDidKey::generate();
    let ucan: Ucan = UcanBuilder::default()
        .for_audience(issuer)
        .claiming_capability(Capability::new(
            UcanResource::OwnedBy(issuer.did()),
            TopAbility,
            EmptyCaveat,
        ))
        .sign(issuer)?;

    // This should work
    assert_matches!(
        Ucan::<DefaultFact, DefaultCapabilityParser>::from_str(&ucan.encode()?),
        Ok(_)
    );

    Ok(())
}

The error message I get:

panicked at 'assertion failed: `Err(TokenParseError { msg: "malformed payload" })` does not match `Ok(_)`'