Proxy can also be configured to use external http service to authenticate clients. But currently, if the external auth service fail to authenticate client, proxy will close the client connection with default message "ERROR: Not authorized by amqpprox proxy". It will be difficult for that client to debug the actual problem in that case. So this PR will propagate the reason, which proxy got from the external http service to the client. And client will immediately be able to know the actual reason in such cases.
Proxy can also be configured to use external http service to authenticate clients. But currently, if the external auth service fail to authenticate client, proxy will close the client connection with default message "ERROR: Not authorized by amqpprox proxy". It will be difficult for that client to debug the actual problem in that case. So this PR will propagate the reason, which proxy got from the external http service to the client. And client will immediately be able to know the actual reason in such cases.