puppetproxy: remove firewall

We don't use puppetproxy since brewster was decommed (https://gerrit.wikimedia.org/r/#/c/96782/), and we don't want someone
setting the role to suddenly get blocked by firewall he wasn't planning on
using. Firewalls go on node level, not role level.

Change-Id: If828eff33fab5f99abcca20a6bc9233970d8e830
Merge "puppetproxy: remove firewall" into production