fix file corruption when proxying an upload to a special remote

The file corruption consists of each chunk of the file being duplicated.
Since chunks are typically a fixed size, it would certianly be possible
to get from a corrupted file back to the original file. But this is still
bad data loss.

Reversion was in commit fcc052bed8.
Luckily that did not make the most recent release.

Annex/Proxy.hs

@@ -210,7 +210,6 @@ proxySpecialRemote protoversion r ihdl ohdl owaitv oclosedv = go
 	storetofile _ _ n [] = pure n
 	storetofile iv h n (b:bs) = do
 		writeVerifyChunk iv h b
-		B.hPut h b
 		storetofile iv h (n - fromIntegral (B.length b)) bs
 
 	proxyget offset af k = withproxytmpfile k $ \tmpfile -> do