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

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https://hg.mozilla.org/integration/gaia-central/rev/04ffc3635d56
Author: Ben Francis <ben@tola.me.uk>
Desc: Merge pull request #18513 from daleharvey/991547

Bug 991547 - Reload tabs when crashed in background. r=benfrancis

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https://hg.mozilla.org/integration/gaia-central/rev/f30e6e640ebc
Author: Dale Harvey <dale@arandomurl.com>
Desc: Bug 991547 - Reload tabs when crashed in background. r=benfrancis
Bumping manifests a=b2g-bump