Bumping gaia.json for 2 gaia-central revision(s)

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https://hg.mozilla.org/integration/gaia-central/rev/a6fef9bc5a24
Author: ochameau <poirot.alex@gmail.com>
Desc: Merge pull request #11486 from ochameau/settingsJS

Bug 904068 - Implement build/settings.py in javascript r=yurenju

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https://hg.mozilla.org/integration/gaia-central/rev/46d191e7abcc
Author: Alexandre Poirot <poirot.alex@gmail.com>
Desc: Bug 904068 - Implement build/settings.py in javascript