Enable firewall by default on NIC level

[MacWeber]

It took me some time to figure out why the firewall configuration on some containers were not taking effect on iptables.
Turns out the firewall rule configuration has no effect if the firewall is not enabled on the virtual NIC level too.

Enabling the firewall on the NIC level by default is harmless, as it does not enable any firewall rules out of the box.

Then, my suggestion is to enable the firewall by default on every VM virtual network interface by adding ,firewall=1 to PCT_OPTIONS:

export PCT_OPTIONS="
  -features $FEATURES
  -hostname $HN
  -net0 name=eth0,bridge=$BRG$MAC,ip=$NET$GATE$VLAN,firewall=1
  -onboot 1
  -cores $CORE_COUNT
  -memory $RAM_SIZE
  -unprivileged $CT_TYPE
  $PW
"