avoid an assert by delaying access to response timestamp when in error

when canceling the sync of a big directory, I can get some network
request that are aborted before a Date reply header has been read

in this case we would always access
AbstractNetworkJob::responseTimestamp() and fire the assert even if we
know that the network reply has an error

delay the access to after the possible errors have been dealt with

Signed-off-by: Matthieu Gallien <matthieu_gallien@yahoo.fr>

src/libsync/propagatedownload.cpp

@@ -635,12 +635,10 @@ void PropagateDownloadFile::slotGetFinished()
     ASSERT(job);
 
     _item->_httpErrorCode = job->reply()->attribute(QNetworkRequest::HttpStatusCodeAttribute).toInt();
-    _item->_responseTimeStamp = job->responseTimestamp();
     _item->_requestId = job->requestId();
 
     QNetworkReply::NetworkError err = job->reply()->error();
     if (err != QNetworkReply::NoError) {
-
         // If we sent a 'Range' header and get 416 back, we want to retry
         // without the header.
         const bool badRangeHeader = job->resumeStart() > 0 && _item->_httpErrorCode == 416;
@@ -711,6 +709,8 @@ void PropagateDownloadFile::slotGetFinished()
         return;
     }
 
+    _item->_responseTimeStamp = job->responseTimestamp();
+
     if (!job->etag().isEmpty()) {
         // The etag will be empty if we used a direct download URL.
         // (If it was really empty by the server, the GETFileJob will have errored