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/c7e53e332dcb
Author: Julien Wajsberg <felash@gmail.com>
Desc: Revert "Merge pull request #13504 from jaoo/927486"

This reverts commit c624b65c1333d2f951533ff5f5d3094681cb1916.