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

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https://hg.mozilla.org/integration/gaia-2_1/rev/669885a32229
Author: jrburke <jrburke@gmail.com>
Desc: Bug 1059100 - [email] Implement XOAUTH2 authentication support for gmail. r=asuth, r=jrburke, r=mcav

landing gelam https://github.com/mozilla-b2g/gaia-email-libs-and-more/pull/336 too
Bumping manifests a=b2g-bump