Move emit callbackReceived signal after returning response to client

The response data to client is sent after emitting QOAuthHttpServerReplyHandler::callbackReceived signal. The problem with this approach that I noticed is that if I listen for QOAuth2AuthorizationCodeFlow::error signal, it doesn't return the client any response on browser until all slots connected to the error signal have been processed. I use the error signal to show a simple message to the user incase there was any authorization error, but the browser is kept in a loading state without receiving any response until the user dismisses the message dialog informing of an error. I think it would be better to move the QOAuthHttpServerReplyHandler::callbackReceived signal after returning a response data. As a result, client side error processing can be done without having to worrying about client timing out waiting for a response.

EDIT: This issue is related to the reply handler class QOAuthHttpServerReplyHandler.