QtHttp: Lower the severity of some log output

The output was only printed if the request was no longer available
queued, meaning that it had been removed before the socket had finished
its connection attempt. That means the result of the attempt is not of
much interest to the user so we should not print it out as a warning.
The reason for why the request was removed from the queue would be the
interesting bit, but it's not covered here.

Task-number: QTBUG-85248
Change-Id: Iac483b8bb600e1577fe88c3699e46d50615bfccb
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
(cherry picked from commit 373285857f5b68537db48244d61de3f755b0d95f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

src/network/access/qhttpnetworkconnection.cpp

@@ -1256,11 +1256,10 @@ void QHttpNetworkConnectionPrivate::_q_hostLookupFinished(const QHostInfo &info)
                 emitReplyError(channels[0].socket, currentReply, QNetworkReply::HostNotFoundError);
             }
         } else {
-            // Should not happen: we start a host lookup before sending a request,
-            // so it's natural to have requests either in HTTP/2 queue, or in low/high
-            // priority queues.
-            qWarning("QHttpNetworkConnectionPrivate::_q_hostLookupFinished"
-                     " could not de-queue request, failed to report HostNotFoundError");
+            // We can end up here if a request has been aborted or otherwise failed (e.g. timeout)
+            // before the host lookup was finished.
+            qDebug("QHttpNetworkConnectionPrivate::_q_hostLookupFinished"
+                   " could not de-queue request, failed to report HostNotFoundError");
             networkLayerState = QHttpNetworkConnectionPrivate::Unknown;
         }
     }