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

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https://hg.mozilla.org/integration/gaia-central/rev/4d2fb3417053
Author: Marcus Cavanaugh <m@mcav.com>
Desc: Merge pull request #22186 from mcav/improved-retry-logic

Bug 1042190 - [Email] Improve IMAP retry logic. r=asuth

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https://hg.mozilla.org/integration/gaia-central/rev/3e7cbc4734dc
Author: Marcus Cavanaugh <m@mcav.com>
Desc: Bug 1042190 - [Email] Improve IMAP retry logic. r=asuth
Bumping manifests a=b2g-bump