Symbiosis: symbiosis-firewall 99-reject file is blank by default
Imported from https://www.github.com/BytemarkHosting/symbiosis/issues/137
Symbiosis' firewall contains a /etc/symbiosis/firewall/incoming.d/99-reject rule by default, which will block connections from 0.0.0.0/0 (anywhere).
If we add an IP to this 99-reject file, connections will only be blocked from this IP and allowed from everywhere else, which isn't usually what we want to happen.
It would be safer if the 99-reject file contained 0.0.0.0/0 by default to avoid allowing more through the firewall than what was intended. This could still be removed from the file if needed.