Fix race in http connection channel

When authentication is cancelled, close the channel instead of the
underlying socket.
The previous behaviour could result in further requests being sent
on the closed socket, which caused errors in case of https over a proxy.

Change-Id: I3dbfc164de4fb29a426c06acaac8f29b9da1d705
Reviewed-by: Peter Hartmann <peter.hartmann@nokia.com>

src/network/access/qhttpnetworkconnection.cpp

@@ -482,7 +482,6 @@ bool QHttpNetworkConnectionPrivate::handleAuthenticateChallenge(QAbstractSocket
             reply->d_func()->errorString = errorDetail(errorCode, socket);
             emit reply->finishedWithError(errorCode, reply->d_func()->errorString);
             // ### at this point the reply could be deleted
-            socket->close();
             return true;
         }
         //resend the request

src/network/access/qhttpnetworkconnectionchannel.cpp

@@ -793,6 +793,9 @@ void QHttpNetworkConnectionChannel::handleStatus()
                     closeAndResendCurrentRequest();
                     QMetaObject::invokeMethod(connection, "_q_startNextRequest", Qt::QueuedConnection);
                 }
+            } else {
+                //authentication cancelled, close the channel.
+                close();
             }
         } else {
             emit reply->headerChanged();