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

========

https://hg.mozilla.org/integration/gaia-2_0/rev/c8110d0b5ea4
Author: Vivien Nicolas <vnicolas@mozilla.com>
Desc: Bug 1031524 - Search Engine based on MNC/MCC in browser.json is not included in the Settings -> Homescreen -> Search Engine. r=benfrancis
Bumping manifests a=b2g-bump