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

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https://hg.mozilla.org/integration/gaia-2_0/rev/ef100ced231d
Author: Sam Foster <sfoster@mozilla.com>
Desc: Bug 1026159 [2.0 uplift] override search result label styles to wrap 2 lines, tighten up grid and search results layout per spec. r=kgrandon
Bumping manifests a=b2g-bump