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

========

https://hg.mozilla.org/integration/gaia-central/rev/475430d6ad52
Author: Amir Nissim <amirnissim@gmail.com>
Desc: Merge pull request #12744 from EverythingMe/924794-browser-uninstall

Bug 924794 - [e.me] Uninstalled app is not removed from Collection

========

https://hg.mozilla.org/integration/gaia-central/rev/493f3857c755
Author: Amir Nissim <amirn@everything.me>
Desc: Bug 924794 - [e.me] Uninstalled app is not removed from Collection