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

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https://hg.mozilla.org/integration/gaia-central/rev/c17860327730
Author: Gabriele Svelto <gsvelto@mozilla.com>
Desc: Bug 1061614 - Properly merge calls that happened in the same day into groups during database upgrades r=Rik
Bumping manifests a=b2g-bump