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

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https://hg.mozilla.org/integration/gaia-1_4/rev/0ff01828970b
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Revert "Bug 960126 - Disable intermittent test on travis, Notification.get(): should work across domains"

This reverts commit fdf7605517f1859e4a28cfd490c057a0bfe6b17a.
Bumping manifests a=b2g-bump