BB 12974: Disable NTLM and Negotiate HTTP Auth

The Mozilla bugs: https://bugzilla.mozilla.org/show_bug.cgi?id=1046421,
https://bugzilla.mozilla.org/show_bug.cgi?id=1261591, #27602

extensions/auth/nsHttpNegotiateAuth.cpp

@@ -145,6 +145,10 @@ nsHttpNegotiateAuth::ChallengeReceived(nsIHttpAuthenticableChannel* authChannel,
   nsIAuthModule* rawModule = (nsIAuthModule*)*continuationState;
 
   *identityInvalid = false;
+
+  /* Always fail Negotiate auth for Tor Browser. We don't need it. */
+  return NS_ERROR_ABORT;
+
   if (rawModule) {
     return NS_OK;
   }

netwerk/protocol/http/nsHttpNTLMAuth.cpp

@@ -167,6 +167,9 @@ nsHttpNTLMAuth::ChallengeReceived(nsIHttpAuthenticableChannel* channel,
 
   *identityInvalid = false;
 
+  /* Always fail Negotiate auth for Tor Browser. We don't need it. */
+  return NS_ERROR_ABORT;
+
   // Start a new auth sequence if the challenge is exactly "NTLM".
   // If native NTLM auth apis are available and enabled through prefs,
   // try to use them.