Incomplete AAR header is generated if there is no own AR header.

[futatuki]

In signing mode, if a message does not have Authentication-Results: header with same authserve-id, openarc milter generates incomplete ARC-Authentication-Results: header such as:

ARC-Authentication-Results: i=1; somehost.example.org

According to RFC8601 Section 2.2, authres-payload should have at least one res info or exact one no-result. So the above should be:

ARC-Authentication-Results: i=1; somehost.example.org ; none