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

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https://hg.mozilla.org/integration/gaia-central/rev/e4a400ba036d
Author: Cristian Rodriguez <crdlc@tid.es>
Desc: Merge pull request #12811 from gitmai/bug-925355-export-url-fb-vcard

Bug 925355 - VCARD not export FB url

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https://hg.mozilla.org/integration/gaia-central/rev/98e5502931d7
Author: mai <mri@tid.es>
Desc: Bug 925355 - VCARD not export FB url