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

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https://hg.mozilla.org/integration/gaia-central/rev/a5040bdcee2c
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 924214 - [Messages] Some test files can't be run in standalone mode r=rwaldron