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

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https://hg.mozilla.org/integration/gaia-central/rev/5de76a77f1bc
Author: Francisco Jordano <fjordano@mozilla.com>
Desc: Revert "Bug 1061662 - [Contacts] Wrong images on contacts when building with GAIA_DEV_PIXELS_PER_PX=1.5"

This reverts commit d3b1cdcbdf4413e3f2cf18bb0fdbf4bf952e9a83.
Bumping manifests a=b2g-bump