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

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https://hg.mozilla.org/integration/gaia-central/rev/0b9f621ff0fc
Author: Amir Nissim <amirnissim@gmail.com>
Desc: Merge pull request #13181 from EverythingMe/919555-remove-appIndex

Bug 919555 - [e.me][perf] Remove app index duplicacy

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https://hg.mozilla.org/integration/gaia-central/rev/2a1dfb60ed7c
Author: Amir Nissim <amirnissim@gmail.com>
Desc: Bug 919555 - [e.me][perf] Remove app index duplicacy [r=ranbena, crdlc]