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

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https://hg.mozilla.org/integration/gaia-central/rev/5424cbc2e534
Author: Julien Wajsberg <felash@gmail.com>
Desc: Revert "Merge pull request #18750 from jmcanterafonseca/oauth_facebook"

This reverts commit 800800b332d03580f4f8748e5046d71f00a3c7d9, reversing
changes made to 7b6b5a4ec6e45fc475105d6a288d77cbb2f17bc2.
Bumping manifests a=b2g-bump