Function deltachat::mimeparser::update_gossip_peerstates

async fn update_gossip_peerstates(
    context: &Context,
    message_time: i64,
    from: &str,
    recipients: &[SingleInfo],
    gossip_headers: Vec<String>,
) -> Result<HashMap<String, SignedPublicKey>>

Parses Autocrypt-Gossip headers from the email and applies them to peerstates. Params: from: The address which sent the message currently being parsed

Returns the set of mail recipient addresses for which valid gossip headers were found.