Comment 8 for bug 1531185

We should make the user more conscious of this behavior and that we have to specify some value in the NTP server so that the clients don't freak out. My first suggestion was to put $fuel_admin_ip there, but that will break time settings for Fuel Master if it points to itself.
In this case, we should make 2 changes:
1 - Fuelmenu should alert that Fuel Master will be used as a time source if no external servers are specified
2 - puppet manifests for nailgun will specify fuel master IP as ntp server if it's empty