ARTEMIS-5697 Close down the proton transport on sasl client failures

When the SASL failure occurs from an outgoing broker connection attempt close
down the transport and detach from the SASL client listener to avoid a loop.

Author: tabish121

artemis-protocols/artemis-amqp-protocol/src/main/java/org/apache/activemq/artemis/protocol/amqp/proton/handler/ProtonHandler.java

@@ -463,6 +463,8 @@ public void onSaslMechanisms(Sasl sasl, Transport transport) {
       if (clientSASLMechanism == null) {
          logger.info("Outbound connection failed - unknown mechanism, offered mechanisms: {}",
                    Arrays.asList(sasl.getRemoteMechanisms()));
+         sasl.setListener(null);
+         transport.close_head();
          dispatchAuthFailed();
       } else {
          sasl.setMechanisms(clientSASLMechanism.getName());