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

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https://hg.mozilla.org/integration/gaia-central/rev/34769c5ab47b
Author: gasolin <gasolin@gmail.com>
Desc: Merge pull request #15750 from gasolin/jsdoc

Bug 950080 - add jsdoc generator to gaia, r=timdream

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https://hg.mozilla.org/integration/gaia-central/rev/9737112a204c
Author: gasolin <gasolin@gmail.com>
Desc: Bug 950080 - add jsdoc generator to gaia
Bumping manifests a=b2g-bump