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

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https://hg.mozilla.org/integration/gaia-central/rev/587092261fce
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #18396 from KevinGrandon/bug_985454_home2_app_grid_zooming

Bug 985454 - [Home2] App Grid Zooming and Reflow

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https://hg.mozilla.org/integration/gaia-central/rev/5e5e93f33d2f
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 985454 - [Home2] App Grid Zooming and Reflow r=me a=gwagner
Bumping manifests a=b2g-bump