Fix GETURLS in external special remote protocol to strip downloader prefix from logged url info before checking for the specified prefix.

This doesn't change what GETURLS returns, but only whether it matches
any prefix that the external special remote asked for.

Logs/Web.hs

@@ -50,7 +50,9 @@ getUrls key = do
 			else return us
 
 getUrlsWithPrefix :: Key -> String -> Annex [URLString]
-getUrlsWithPrefix key prefix = filter (prefix `isPrefixOf`) <$> getUrls key
+getUrlsWithPrefix key prefix = filter (prefix `isPrefixOf`) 
+	. map (fst . getDownloader)
+	<$> getUrls key
 
 setUrlPresent :: UUID -> Key -> URLString -> Annex ()
 setUrlPresent uuid key url = do