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

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https://hg.mozilla.org/integration/gaia-central/rev/610dda30df47
Author: AxelR <aroyerb@gmail.com>
Desc: Bug 981572 - No forward buttons on undownloaded MMS r=julien
Bumping manifests a=b2g-bump