[Samba] Problem using local groups when winbind is running

[Adam Nielsen]

> Even after getting all such errors cleared though, I still can't access
> the shares which are using the 'valid users = @localgroup'
> configuration. I've tried changing that to 'valid users = +localgroup'
> which should only check NSS but that also fails.

Since you're on a domain you might have to specify that the groups are
local, e.g. @MACHINENAME\localgroup, as it might default to your domain
if one is not given explicitly.

I'm not sure how this works when winbind isn't running, but it should be
okay.

Cheers,
Adam.