Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-2_0/rev/c4cb7d5f41a5
Author: James Burke <jrburke@gmail.com>
Desc: Merge pull request #21123 from jrburke/bug1025727-v2.0-email-cronsync-failsafe

Bug 1025727 - [email/cronysync] Failsafe abort/window.close after (multiple?) failed cronsync(s) r=mcav a=bajaj

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https://hg.mozilla.org/integration/gaia-2_0/rev/200072e639db
Author: jrburke <jrburke@gmail.com>
Desc: Bug 1025727 - [email/cronysync] Failsafe abort/window.close after (multiple?) failed cronsync(s)

Cherry pick of e64d7adf507d0f0164988257d30600499b1e5776 for v2.0 with manual change of
adding `evt = require('evt')`
Bumping manifests a=b2g-bump