Revert "fuel_upgrade: add KillSupervisord hook"

We don't need to kill supervisor, because
during host-system upgrade we don't restart
supervisor anymore
https://review.openstack.org/#/c/115315/
https://review.openstack.org/#/c/112077/

As result when we kill container in pre-upgrade
hook, nobody runs it and upgrade fails because
we use supervisor during docker containers
upgrade.

Related-Bug: #1358144
This reverts commit 71e55fe025a38e4c734a41e2e202462f0c29e7e0.

Change-Id: I0329b5110d632ac675f7d2e12c64c9ca4ea446d3
Merge "Revert "fuel_upgrade: add KillSupervisord hook""