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

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https://hg.mozilla.org/integration/gaia-central/rev/f8f42fe2d149
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Revert "Bug 1104198 - Make DESKTOP builds work with mulet."

This reverts commit cb501ab9552703691f8752882397daddcf7eb1fd.
Bumping manifests a=b2g-bump