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

========

https://hg.mozilla.org/integration/gaia-central/rev/68cb800422d0
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 1035936 - Disable test, TEST-UNEXPECTED-FAIL | /builds/slave/test/gaia/apps/search/test/marionette/app_search_test.js | Search - App search Search for app with entry point
Bumping manifests a=b2g-bump