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

========

https://hg.mozilla.org/integration/gaia-central/rev/1ba76f61ac87
Author: BavarianTomcat <tomcat@mozilla.com>
Desc: Revert "Bug 1070442 - Support building gaia apps in parallel" for bustage

This reverts commit de3d85cb383bacf221566be4749874270ebab843.
Bumping manifests a=b2g-bump