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

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https://hg.mozilla.org/integration/gaia-central/rev/64b67a585ea1
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #16046 from KevinGrandon/bug_968832_rocketbar_url_editing

Bug 968832 - [Rocketbar] Basic URL functionality

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https://hg.mozilla.org/integration/gaia-central/rev/7f89c39b87b4
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 968832 - [Rocketbar] Basic URL functionality r=benfrancis
Bumping manifests a=b2g-bump