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

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https://hg.mozilla.org/integration/gaia-central/rev/e390a0994ad0
Author: Evyatar Amitay <evyatron@gmail.com>
Desc: Merge pull request #12706 from EverythingMe/marketplace-launch

[Bug 924080] Open marketplace links in browser [r=ranbena]

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https://hg.mozilla.org/integration/gaia-central/rev/7119c82b8409
Author: Evyatar Amitay <evyatron@gmail.com>
Desc: [Bug 924080] Open marketplace links in browser [r=ranbena]