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

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https://hg.mozilla.org/integration/gaia-central/rev/0acabc6a8619
Author: evelynhung <jj.evelyn@gmail.com>
Desc: Merge pull request #12942 from flodolo/bug928347

Bug 928347 - Add missing strings in settings.en-US.properties, r=evelyn

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https://hg.mozilla.org/integration/gaia-central/rev/844741327628
Author: Francesco Lodolo <flod@lodolo.net>
Desc: Bug 928347 - Add missing strings in settings.en-US.properties

All strings have the correct data-l10n-id but strings are not available
in the .properties file