netcmd: Ignore rIDUsedPool attribute in offline domain backup test

netcmd: Ignore rIDUsedPool attribute in offline domain backup test

The RID Set of the newly created DC account has all its values
initialised to zero. If the rIDUsedPool attribute was previously
non-zero, then the restore process will cause its value to change.

BUG: https://bugzilla.samba.org/show_bug.cgi?id=14669

Signed-off-by: Joseph Sutton <josephsutton@catalyst.net.nz>
Reviewed-by: Andrew Bartlett <abartlet@samba.org>
Reviewed-by: Douglas Bagnall <douglas.bagnall@catalyst.net.nz>
(cherry picked from commit 658e5a6cc20b57f48477affd370fe25458178b92)