Updated fwupd and fwupdate repos wrt the JSON signing setup

[Steve McIntyre <steve@einval.com>]

Hey folks,

I've just tweaked the JSON for fwupd and fwupdate to match Ansgar's
updated spec. I *think* that we're ready to switch to the production
key - I certainly don't know of any blockers. Mario: please confirm
that you're happen and we can upload.

-- 
Steve McIntyre, Cambridge, UK.                                steve@einval.com
"...In the UNIX world, people tend to interpret `non-technical user'
 as meaning someone who's only ever written one device driver." -- Daniel Pead