Add ntpdate_hosts to rc.conf

[John Marshall]

> Is there a reason you are using ntpdate rather than ntpd?  ntpdate is 
> supposedly deprecated and ntpd can do what ntpdate does:
> 
>      -q      Exit the ntpd just after the first time the clock is set.
This
>              behavior mimics that of the ntpdate(8) program, which is
to be
>              retired.  The -g and -x options can be used with this
option.
> 
> --Alex

Perhaps a better question, along the same lines, would be, Why does the
FreeBSD RC system use ntpdate?

If the idea is to disappear the ntpdate phase from startup, then let's
ditch it and add the -g flag as default for ntpd_flags. If ntpdate is
staying, for the time being, then it can't hurt to add a missing
defaults variable, can it?

John.