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/cd27aff10555
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #13301 from julienw/931767-fix-test-only a=tests

Bug 931767 - fix tests for the DST change only r=rwaldron(cherry picked from commit 19eeb4de77def88ea967d4b1d79bae4df05b523b)