Need to describe that we need restart ntpd in case of resuming suspended master node manually

That created due to https://bugs.launchpad.net/fuel/+bug/1421965

If you can't or don't want to do resume master node VM with dos.py - please, do next steps after master node resume (and before bootstraps start):
 -- stop ntpd (do /etc/init.d/ntpd stop)
 -- restart ntpdate (do /etc/init.d/ntpd restart)
 -- start ntpd (do /etc/init.d/ntpd start)

It should be written in documentation, cause in other case number of deployments will fail.