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

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https://hg.mozilla.org/integration/gaia-central/rev/e9c911f07ff4
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Merge pull request #21573 from crdlc/bug-1036823

Bug 1036823 - [Vertical homescreen] Remove "install" message for bookmarks because it is not supported r=kgrandon

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https://hg.mozilla.org/integration/gaia-central/rev/8238971ce4ab
Author: crdlc <crdlc@tid.es>
Desc: Bug 1036823 - [Vertical homescreen] Remove "install" message for bookmarks because it is not supported
Bumping manifests a=b2g-bump