Bumping gaia.json for 1 gaia-central revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/ff1e217c8170
Author: Fabien Cazenave <fabien@cazenave.cc>
Desc: Revert "Merge pull request #13928 from vingtetun/bug928612"

This reverts commit 76108aa3cb65f9bfa20e2fdb8c103e4940d1b811, reversing
changes made to 1cd5bef43a577ef2256a048269a4926c0f492470.