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

========

https://hg.mozilla.org/integration/gaia-central/rev/d56d449c7476
Author: Mike Pennisi <mike@mikepennisi.com>
Desc: Bug 883813 - [SMS][Translation][Spanish][Portugues] Some tokens are not translated r=julienw

In order to support a variable width of the "To:" field in the
Recipients section, some restructuring is necessary.

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "75423c872bf4517f2ec83227981879ca71a6daa1", 
+    "revision": "d56d449c7476dfc57d238756eed167f38ef18922", 
     "repo_path": "/integration/gaia-central"
 }