static range. This is done only when the chilli_range_split variable
is defined (still undefined by default, for the moment must manually
defined by the admin in /etc/fuss-server/fuss-server-defaults.yaml).

The coova-chilli net is just split in a half, computing the subnets
from the value saved in the hotspot_network variable (saved in
/etc/fuss-server/fuss-server.yaml) that's configured the first time
fuss-server cp is run.