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

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https://hg.mozilla.org/integration/gaia-central/rev/2d9efd61d043
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #21899 from yurenju/wlach-1039739

Bug 1039739 - Add some logging when writing the git commit id into the s... r=@yurenju

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https://hg.mozilla.org/integration/gaia-central/rev/cd79430fcc38
Author: William Lachance <wlachance@mozilla.com>
Desc: Bug 1039739 - Add some logging when writing the git commit id into the settings app;r=yurenju
Bumping manifests a=b2g-bump