The admin must always own this name. If another entry has this
value set then remove it.
There is a uniqueness plugin for this attribute so the only two
possibilities are:
- no entry has this value set
- the admin user has this value set
- a different entry has the value set
Still, for robustness purposes, the upgrade plugin will handle
more entries.
Signed-off-by: Rob Crittenden <rcritten@redhat.com>