check if quvi page url has already been downloaded before

That is the url that is typically stored in the git-annex branch.

Kept the check for the video url too, just in case.

Command/ImportFeed.hs

@@ -134,7 +134,7 @@ performDownload relaxed cache todownload = case location todownload of
 	Enclosure url -> checkknown url $
 		rundownload url (takeExtension url) $ 
 			addUrlFile relaxed url
-	QuviLink pageurl -> do
+	QuviLink pageurl -> checkknown pageurl $ do
 		mp <- withQuviOptions Quvi.query [Quvi.quiet, Quvi.httponly] pageurl
 		case mp of
 			Nothing -> return False