zfs allow reports empty username

[Nikos Vassiliadis]

Hi,

On a backup server that runs FBSD-11.2-RELEASE I noticed that
'zfs allow' reports an empty username:> root at hermes:~ # zfs allow storage
> ---- Permissions on storage ------------------------------------------
> Local+Descendent permissions:
>         user backup compression,create,destroy,groupquota,groupused,mount,mountpoint,receive,snapdir,sync,userprop,userquota,userused
>         user  compression,create,destroy,groupquota,groupused,mount,mountpoint,receive,sync,userprop,userquota,userused

I don't recall adding a username and later removing it. Any ideas how to
remove this?

Thanks in advance!
Nikos