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

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https://hg.mozilla.org/integration/gaia-1_2/rev/158dd6157484
Author: Arthur Chen <crh0716@gmail.com>
Desc: Bug 912020 - Save to settings DB when leaving the panel

Conflicts:
	apps/settings/js/settings.js