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

========

https://hg.mozilla.org/integration/gaia-central/rev/ca8a474b40f9
Author: Eric O'Connor <eric@bocoup.com>
Desc: Bug 934722 - [clock] Unit tests compute timezone offset incorrectly - r=gnarf

Closes gh-13366

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "e9d3946c6e4c26c60f67b8efac40e14785b634d3", 
+    "revision": "ca8a474b40f98dfe6ca4e51d8af5c21d36139aab", 
     "repo_path": "/integration/gaia-central"
 }