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

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https://hg.mozilla.org/integration/gaia-2_0/rev/f95181331546
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Revert "Bug 1069157 - [PDF Viewer] update pdf.js in Gaia"

This reverts commit 414f2ff5c7d000e151b970df3871f63082e4a300.
Bumping manifests a=b2g-bump