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

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https://hg.mozilla.org/integration/gaia-central/rev/641fa70735be
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #25537 from etiennesegonzac/bug-1088427-homescreen-orientationchange

Bug 1088427 - Make sure the homescreen fade overlay resizes properly on orientationchange r=kgrandon

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https://hg.mozilla.org/integration/gaia-central/rev/e39de5d904d2
Author: Etienne Segonzac <etienne@segonzac.info>
Desc: Bug 1088427 - Make sure the homescreen fade overlay resizes properly on orientationchange.
Bumping manifests a=b2g-bump