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

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https://hg.mozilla.org/integration/gaia-central/rev/cb9984d42127
Author: Arnau <arnau@arnaumarch.com>
Desc: Merge pull request #18078 from rnowm/993388

Bug 993388 - [Followup][Messages][Refresh] Messages Inbox edit mode r=julienw

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https://hg.mozilla.org/integration/gaia-central/rev/bf1f0f6d8f73
Author: rnowm <arnau@arnaumarch.com>
Desc: Bug 993388 - [Followup][Messages][Refresh] Messages Inbox edit mode
Bumping manifests a=b2g-bump