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

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https://hg.mozilla.org/integration/gaia-central/rev/5c3267470efd
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #15818 from julienw/965561-use-gaia-optimize-email-build

Bug 965561 - [email] default to not optimize if GAIA_OPTIMIZE=1 is not s...

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https://hg.mozilla.org/integration/gaia-central/rev/7154646d7c59
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 965561 - [email] default to not optimize if GAIA_OPTIMIZE=1 is not set r=jrburke
Bumping manifests a=b2g-bump