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

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https://hg.mozilla.org/integration/gaia-central/rev/47459a0d67fa
Author: Andrew Sutherland <asutherland@asutherland.org>
Desc: Merge pull request #24927 from asutherland/email-getbody-fix

Bug 1070429 - [email/IMAP] premature saving leads to missing bodies. r=jrburke

propagation of mozilla-b2g/gaia-email-libs-and-more#343

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https://hg.mozilla.org/integration/gaia-central/rev/7c12bf285d25
Author: Andrew Sutherland <asutherland@asutherland.org>
Desc: Bug 1070429 - [email/IMAP] premature saving leads to missing bodies. r=jrburke

propagate back-end fix
https://github.com/mozilla-b2g/gaia-email-libs-and-more/pull/343
Bumping manifests a=b2g-bump