disable-chef-client isn't preserved over reboots
In production#2570 (comment 401672637) we saw that disabling chef-client with disable-chef-client
wasn't preserved over a reboot - which unexpectedly brought the DB back into rotation with a high replication delay.
We need to figure out why it isn't preserved over reboots (the node was in an unhealthy state, so maybe it just failed to write changes to disk in this one case and works in general - need to test) and fix it.