[daip] KRING fails on flagged IF: Fixed

[Shami Chatterjee]

> I suspect the flagged IF itself is not the problem.
> -- ketan

Hi:
Well for this specific data set at least, Chris's patch fixes the
problem, and FRING, KRING return near-identical results.

I've seen another problem with KRING before, when trying to fringe-fit
with a CC model: that might be something deeper (I'll gripe if/when I can
reproduce it). 

But this one seems fixed for now.
Thanks!
Shami