[Xastir] Proper setup for NWS alerts to RF

[Tyler Allison]

> I thought it was documented in some of the README's, INSTALL, or
> online doc files.  Check there.  Sorry nobody responded earlier.  I
> don't run an igate, so I haven't dealt with that stuff in a while.

It is..I just didnt look hard enough. ;)

> It's also possible that you're not gating it at all, by
> incorrect settings on an interface or in the Configure->Defaults
> dialog

That was the problem. I had turned on RF gating in one location but I had
not turned on the 'global' setting for RF gating. Highly annoying.

-Tyler