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

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https://hg.mozilla.org/integration/gaia-central/rev/c792b0e961f7
Author: Hubert Figuière <hub@figuiere.net>
Desc: Merge pull request #16276 from hfiguiere/bug962040

Bug 962040 - Add bug # in comments to reenable apps. r=julienw

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https://hg.mozilla.org/integration/gaia-central/rev/34a18168af19
Author: Hubert Figuière <hub@figuiere.net>
Desc: Bug 962040 - Add bug # in comments to reenable apps.
Bumping manifests a=b2g-bump