AsyncHttpClient: SCRAM and Digest mutual-authentication responses are not verified

The AsyncHttpClient (AHC) library allows Java applications to easily execute HTTP requests and asynchronously process HTTP responses. From 3.0.8 until 3.0.12, processScramAuthenticationInfo and processAuthenticationInfo compute the SCRAM ServerSignature or Digest rspauth verification result but log a mismatch and still deliver the response as authenticated. On a non-TLS or compromised transport, a peer that has not proved knowledge of the shared secret can therefore be accepted as the server. The fix rejects a present invalid value and computes Digest rspauth from the Authorization parameters actually sent, but verification remains unenforced when the value is absent, the sent parameters cannot be recovered, or Digest uses qop=auth-int. This issue is fixed in version 3.0.12.