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

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https://hg.mozilla.org/integration/gaia-central/rev/86e06b1db110
Author: Corey Frang <gnarf37@gmail.com>
Desc: Bug 927330 - [Clock][Timer] The countdown is not normally(un-countdown) while clicking pause/resume button quickly. - r=jugglinmike

- Fix timer math for ticks