Function admit 

fn admit(
    state: &AppState,
    did: &str,
    target: &Target<'_>,
    lxm: &str,
) -> Result<InFlight, ApiError>

Spends one of did’s proxied calls, or answers the refusal.

Logged at WARN, naming the account and the target: a refusal here is an account calling faster or wider than an agent does.