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

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https://hg.mozilla.org/integration/gaia-central/rev/429d6cd4a97d
Author: Doug Sherk <github@sherk.me>
Desc: Revert "Bug 1078448 - Modify call_screen_window.js reloadWindow to not leak CallScreen app instances. r=drs."

This reverts commit 80ef9919169638b0659268d736e4873938dd7ba9.
Bumping manifests a=b2g-bump