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

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https://hg.mozilla.org/integration/gaia-central/rev/fb5a4aa15e26
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #24444 from julienw/1073139-fix-settings-test-newer-mocha

Bug 1073139 - [Settings] fix settings tests with a newer mocha r=arthurc...

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https://hg.mozilla.org/integration/gaia-central/rev/887d961bfb39
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 1073139 - [Settings] fix settings tests with a newer mocha r=arthurcc
Bumping manifests a=b2g-bump