Bumping gaia.json for 1 gaia-central revision(s) a=gaia-bump

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https://hg.mozilla.org/integration/gaia-central/rev/5e851aef150b
Author: Kyle Machulis <kyle@nonpolynomial.com>
Desc: Revert "Bug 927642 - Fix dir/lang integration tests for notifications"

This reverts commit 9fc08c1790d49b0cb64e0c8e04da141cbd2fd2a1.