5b79ab7e5 - bump piston dependency, drop now useless monkeypatch
4117bcf3b - drop monkeypatch for piston emitter, since it's been fixed in piston itself
Don't return ipv6 boot addresses for ipv4 subnets.
An ipv4 subnet won't be able to use ipv6 addresses, and it would break the
DHCP config.
(cherry picked from commit 425a78cfd666e05757bf6f72e63c48bdf0f807df)
LP #1992330: Use the rack controller IP as DNS when relaying DHCP
Add relay rack ips as DNS servers
This patch aims to add the rack controll IP addresses of the relay
vlan as DNS servers.
This fixes an issue that when there are no other settings or available
IPs, MAAS adds only the IP address of the region controller, but
sometimes the region controller might not be routed to that vlan, hence
this patch, as the rack controllers should always be reachable by the
machines.
(cherry picked from commit 65a0cacf6aa37704195e0165ee69e2c516fb6936)