Code review comment for lp:~julian-edwards/maas/release-notes-1.7

We should also add a note re: https://bugs.launchpad.net/ubuntu/+source/maas/+bug/1379144 to point out that maas-proxy isn't installed by default on upgrade; if you want to use it instead of squid-deb-proxy you need to install it manually (it will remove squid-deb-proxy).

Telling you here rather than working up a branch since this hasn't landed yet :)