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

========

https://hg.mozilla.org/integration/gaia-central/rev/60bf20cba4da
Author: Adam Hyland <protonk@gmail.com>
Desc: Bug 936646 - [Messages][Drafts] Implement local storage for drafts r=rwaldron

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "7611ec39f2668d09a807b5e47b5ea810c8c00899", 
+    "revision": "60bf20cba4daf5f05870826c1f2735b0b3ea161a", 
     "repo_path": "/integration/gaia-central"
 }