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

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https://hg.mozilla.org/integration/gaia-central/rev/50fddaae85a2
Author: Michael Wu <mwu@mozilla.com>
Desc: Merge pull request #10406 from michaelwu/bug-871501

Bug 871501 - Make zip file generation consistent

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https://hg.mozilla.org/integration/gaia-central/rev/6c5016942202
Author: Michael Wu <mwu@mozilla.com>
Desc: Bug 871501 - Make zip file generation consistent