Bumping gaia.json for 2 gaia-1_2 revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-1_2/rev/345ffac7c29d
Author: Teodosia Pop <teodosia.pop@gmail.com>
Desc: Merge pull request #13669 from bobsilverberg/v1.2_tbpl_up

Bug 934446 - Test Messages contact input validation

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https://hg.mozilla.org/integration/gaia-1_2/rev/2b882dc87def
Author: Bob Silverberg <bob.silverberg@gmail.com>
Desc: Bug 934446 - Test Messages contact input validation