ol-home0 provisioning needs rsync ferm/input

[mekarpeles]

The issue was that we were updating /etc/ferm/ferm.conf rules even though these were auto-generated daily. We should have been putting them in /etc/ferm/input/ as is described in @abezella's guide:
https://docs.google.com/document/d/1W4DtLPlzCUszovOj1yA6uy5Ws8GY_cpjlxu5VOo2aQo/edit#heading=h.3dy6vkm

The second issue is, restarting ferm via sudo service ferm reload causes Docker iptables to go haywire.
The solution is to restart docker with sudo systemctl restart docker

HOW DO WE DETECT FERM RULES CHANGES FROM ANSIBLE.

• If we reprovision ol-home0 this ferm/input rule needs to be a step, e.g. adding:
  saddr $CLUSTER proto tcp dport rsync ACCEPT;
  to /ol-home0:/etc/ferm/input/rsync.conf

Related to #680

Originally posted by @mekarpeles in #4706 (comment)

[cclauss]

Rsync works between ol-home0 and ol-www0. We will reopen this if we run into rsync issues.