Bumping gaia.json for 2 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/c8ac536548db
Author: autolander <bug.autolander@gmail.com>
Desc: Bug 1103629 - merge pull request #26384 from KevinGrandon:bug_1103629_marionette_client_loader_verticalhome to mozilla-b2g:master

========

https://hg.mozilla.org/integration/gaia-central/rev/a1796499b69e
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 1103629 - [HomeScreen] Use a marionette client loader to include the home screen app

b2g/config/gaia.json

@@ -4,6 +4,6 @@
         "remote": "", 
         "branch": ""
     }, 
-    "revision": "55dad48c2099b7bad629d56ebcc6ddfd5fe09a8c", 
+    "revision": "c8ac536548dbbda88d8730b21068ff9779950d8c", 
     "repo_path": "integration/gaia-central"
 }