avoid possibly re-adding a removed transfer when updating its info

Doesn't fix the bug I thought it'd fix, but is clearly correct.

Assistant/Threads/TransferPoller.hs

@@ -41,8 +41,7 @@ transferPollerThread st dstatus = do
 				sz <- catchMaybeIO $
 					fromIntegral . fileSize
 						<$> getFileStatus f
-				when (bytesComplete info /= sz && isJust sz) $ do
-					putStrLn $ "download size " ++ show sz
+				when (bytesComplete info /= sz && isJust sz) $
 					updateTransferInfo dstatus t info
 						{ bytesComplete = sz }
 			{- can't poll uploads -}

Assistant/Threads/TransferWatcher.hs

@@ -64,7 +64,7 @@ onAdd st dstatus file _ = case parseTransferFile file of
 				]
 			r <- headMaybe . filter (sameuuid t) . knownRemotes
 				<$> getDaemonStatus dstatus
-			updateTransferInfo dstatus t info
+			alterTransferInfo dstatus t info
 				{ transferRemote = r }
 		sameuuid t r = Remote.uuid r == transferUUID t