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

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https://hg.mozilla.org/integration/gaia-central/rev/c760012bdd6b
Author: Florin Strugariu <bebef_1987@yahoo.com>
Desc: Merge pull request #14221 from zacc/bug_942107_contacts

Bug 942107 - Be smarter about locators in Contacts app

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https://hg.mozilla.org/integration/gaia-central/rev/c399befe2dea
Author: Zac Campbell <zcampbell@mozilla.com>
Desc: Bug 942107 - Be smarter about locators in Contacts app