Fix append .!qB extension when it disabled.

src/core/bittorrent/torrenthandle.cpp

@@ -206,6 +206,7 @@ TorrentHandle::TorrentHandle(Session *session, const libtorrent::torrent_handle
     if (!data.resumed) {
         if (hasMetadata()) {
             setFirstLastPiecePriority(data.sequential);
+            if (m_session->isAppendExtensionEnabled())
                 appendExtensionsToIncompleteFiles();
         }
     }
@@ -1550,6 +1551,7 @@ void TorrentHandle::handleMetadataReceivedAlert(libt::metadata_received_alert *p
     Q_UNUSED(p);
     qDebug("Metadata received for torrent %s.", qPrintable(name()));
     updateStatus();
+    if (m_session->isAppendExtensionEnabled())
         appendExtensionsToIncompleteFiles();
     m_session->handleTorrentMetadataReceived(this);