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

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https://hg.mozilla.org/integration/gaia-central/rev/49d3060f3a16
Author: Alive.Kuo <alegnadise@gmail.com>
Desc: Merge pull request #16109 from desaintmartin/952912

Bug 952912 - System update check for NOFTU build, r=alive

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https://hg.mozilla.org/integration/gaia-central/rev/a371e438a37f
Author: Cédric de Saint Martin <cedric.dsm@tiolive.com>
Desc: Bug 952912 - Check for update is on even for NOFTU builds.
Bumping manifests a=b2g-bump