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

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https://hg.mozilla.org/integration/gaia-central/rev/90c5e3b6bc76
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 1066607 - Use the BrowserConfigHelper for new tabs to fix the missing origin issues. r=daleharvey
Bumping manifests a=b2g-bump