[OE-core] Cache unihash ... doesn't match BB_UNIHASH ...

[chris.laplante at agilent.com]

> > Anecdotally, we are running Zeus for nightly builds with three
> > multiconfigs. I cherry-picked your "bitbake: fix2" and "bitbake:
> > fixup" patches and haven't seen any of the BB_UNIHASH errors since.
> > Granted it's only been a week. But before that, hash equiv +
> > multiconfig was unusable due to the BB_UNIHASH errors.
> 
> That is a really helpful data point, thanks. I should probably clean up
> those bitbake patches and get them merged then, I couldn't decide if
> they were right or not...

Sure thing! I should note, I did delete my hashserv.db (on the hash equiv server) out of caution after applying those patches. 

Chris