[BUG] LDAP users are created in `privileged` group by default

[mfontana-elem]

When trying to create users using the cluster utility, by default users are given super user rights.

The fix is to simply change line 164 in the following way

@click.option('-g', '--gid', default="9876", help='Add to this groupID')

to

@click.option('-g', '--gid', default=None, help='Add to this groupID')