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

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https://hg.mozilla.org/integration/gaia-central/rev/8d7dcb6cae85
Author: Fabrice Desré <fabrice@desre.org>
Desc: Merge pull request #22676 from fabricedesre/bug1050423

Bug 1050423 - Killing an app that has an open permissions dialog leaks t...

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https://hg.mozilla.org/integration/gaia-central/rev/291800a02d67
Author: Fabrice Desré <fabrice@desre.org>
Desc: Bug 1050423 - Killing an app that has an open permissions dialog leaks the ContentParent r=alive
Bumping manifests a=b2g-bump