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

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https://hg.mozilla.org/integration/gaia-central/rev/61aa76750918
Author: Andrew Sutherland <asutherland@asutherland.org>
Desc: Merge pull request #21967 from asutherland/email-op-callbacks-after-save

Bug 1039007 - [email/backend] Do not invoke operation callbacks until after any associated saves have safely hit the disk. r=mcav

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https://hg.mozilla.org/integration/gaia-central/rev/5226b069d4a3
Author: Andrew Sutherland <asutherland@asutherland.org>
Desc: Bug 1039007 - [email/backend] Do not invoke operation callbacks until after any associated saves have safely hit the disk. r=mcav

landing https://github.com/mozilla-b2g/gaia-email-libs-and-more/pull/323
Bumping manifests a=b2g-bump