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

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https://hg.mozilla.org/integration/gaia-central/rev/919ce29eb9e2
Author: Gabriele Svelto <gsvelto@mozilla.com>
Desc: Merge pull request #10603 from gabrielesvelto/bug-877482

Bug 877482 - Remove workaround for bug 850941 to handle file within blobs correctly r=djf

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https://hg.mozilla.org/integration/gaia-central/rev/c5d8a2427f1f
Author: Gabriele Svelto <gabriele.svelto@gmail.com>
Desc: Bug 877482 - Remove workaround for bug 850941 to properly handle file-backed blobs