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

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https://hg.mozilla.org/integration/gaia-central/rev/1a1827fe8389
Author: Francisco Jordano <arcturus@ardeenelinfierno.com>
Desc: Merge pull request #12756 from arcturus/bug-924890

Bug 924890 - [Contacts] Javascript error after landing bug 902873 (merge error)

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https://hg.mozilla.org/integration/gaia-central/rev/02c02542fc1f
Author: Francisco Jordano <arcturus@ardeenelinfierno.com>
Desc: Bug 924890 - [Contacts] Javascript error after landing bug 902873 (merge error)