[Borgbackup] ACLs not preserved

[Thomas Waldmann]

 >> it would be good if you could reproduce with the normal push mode.
 > I just gave it a shot on push mode, and both mount and extract show
 > the same issue.

OK, guess it makes sense to open an issue on github about this.

Do NOT refer to special pull mode, but post a minimal push-mode 
reproducer script that shows the issue when executing it.

If you can reproduce even with a local repo, use a local repo.