firewall_trusted_ipv6 was gone by r202460.  Remove stale comment about it as well.
firewall_trusted_ipv6 was gone by r202460.  Remove stale comment about
it as well.

jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase,jrobhoward/SCADAbase