Ensure cron absent for misc::nfs-server::home::backup

A little background:

This is a "service" where fenari's home, in reality /vol/home_pmtpa on
the netapps is backed up on nfs-1. The backup method is an rsync with an
ssh key to a certain user called, confusingly, db20. The other end-point
is tridge, the old backup server. Probably in the interest of keeping
history, --delete was not passed to rsync, the end result being some
very very old files that probably violated our new Data Retention
policy. Ensure the cron is absent for now. Disable the entire service
in subsequent patches

Change-Id: Iff8bf1f399d97ee8d78d361e48a3c0e674e2e5ff
Merge "Ensure cron absent for misc::nfs-server::home::backup" into production