Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/6ee0334bda22
Author: Hubert Figuière <hub@figuiere.net>
Desc: Merge pull request #15423 from hfiguiere/bug958652-2

Bug 958652 - Part 2: MOZPERFOUT must be passed on in the Makefile. r=davehunt

========

https://hg.mozilla.org/integration/gaia-central/rev/bc6351114065
Author: Hubert Figuière <hub@figuiere.net>
Desc: Bug 958652 - Part 2: MOZPERFOUT must be passed on in the Makefile.