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

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https://hg.mozilla.org/integration/gaia-central/rev/581a7d1786bb
Author: Pavel Ivanov <pivanov@mozilla.com>
Desc: Revert "Merge pull request #13981 from pivanov/bug-939209"

This reverts commit c0a272eaa8c36ce620a6c6eeae9bf90dc620a357, reversing
changes made to bb8d98559cdbec4088c0ecf9d630993378df1e4c.