Update cb_cmds commands to refuse reservations in remote-subnet4-set
If there is a reservations entry in the subnet definition:
- throw if it is not a list
if it is not empty warn and remove it before parsing
- if it is not empty return an error
Please edit this and remove one of the choices when the list if not empty. IMHO the last one is better: drastic but do not suggest reservations were added to the database.