HTTP: Don't call allDone twice

Change-Id: Ia3fb2e2c185f4e61234ce237416028b0c45357f8
Reviewed-by: Edward Welbourne <edward.welbourne@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

src/network/access/qhttpprotocolhandler.cpp

@@ -216,6 +216,8 @@ void QHttpProtocolHandler::_q_receiveReply()
             }
       case QHttpNetworkReplyPrivate::AllDoneState:
             m_channel->allDone();
+            if (state == QHttpNetworkReplyPrivate::AllDoneState)
+                lastBytes = bytes; // No need to loop more just to call m_channel->allDone again.
             break;
         default:
             break;