Comment 10 for bug 1263934

Code review:
https://review.openstack.org/68670

This is the only solution that will please everyone:
It should be simpler to be able to start using
Fuel with no gateway or DNS. Therefore, NTP
will default to disabled with no valid gateway
configured. In most deployments, except those
in automated tests where dhcp_interface option
is provided in kernel options, NTP will be
disabled until the user re-enables it after
configuring their gateway.