Improve display when git config download from a http remote fails.

The error message displayed used to only come from curl/wget and perhaps
was clearer than the one displayed now that http-client is used. In any
case, it does make sense to hide it because git-annex prints its own
warning message.

This commit was sponsored by Jake Vosloo on Patreon.

Remote/Git.hs

@@ -254,7 +254,7 @@ tryGitConfigRead autoinit r
 		v <- liftIO $ withTmpFile "git-annex.tmp" $ \tmpfile h -> do
 			hClose h
 			let url = Git.repoLocation r ++ "/config"
-			ifM (Url.download nullMeterUpdate url tmpfile uo)
+			ifM (Url.downloadQuiet nullMeterUpdate url tmpfile uo)
 				( Just <$> pipedconfig "git" [Param "config", Param "--null", Param "--list", Param "--file", File tmpfile]
 				, return Nothing
 				)