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

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https://hg.mozilla.org/integration/gaia-1_4/rev/5c378c7c7486
Author: Viorela Ioia <viorelaioia@gmail.com>
Desc: Bug 1003411 - [functionaltest] Investigate and/or fix test_gallery_view.py
Bumping manifests a=b2g-bump