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

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https://hg.mozilla.org/integration/gaia-central/rev/a711c707e769
Author: Yuren Ju <yurenju@gmail.com>
Desc: Merge pull request #14280 from bhearsum/master

Disable e-mail notification because it's Very Spammy. r=yurenju

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https://hg.mozilla.org/integration/gaia-central/rev/98bfc5dd5594
Author: bhearsum <bhearsum@gmail.com>
Desc: Disable e-mail notification because it's Very Spammy.