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

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https://hg.mozilla.org/integration/gaia-central/rev/944559e6e60f
Author: KWierso <kwierso@gmail.com>
Desc: Revert "Bug 1029336 - Only disable contextmenu for certified apps. r=alive" for Gaia-unit failures on TBPL

This reverts commit 163f259fc7c8a01e3265c050094767e3ad523b80.
Bumping manifests a=b2g-bump