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

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https://hg.mozilla.org/integration/gaia-central/rev/1a68453b0a52
Author: Ryan VanderMeulen <ryanvm@gmail.com>
Desc: Revert "Merge pull request #17275 from cctuan/979827"

This reverts commit 11d6cd3d50c5a92a85a738a8de5a36932c8a89e6, reversing
changes made to ce8a5f8153d45000e39fc9e4b2b94521747015c3.
Bumping manifests a=b2g-bump