Bumping gaia.json for 2 gaia-central revision(s)

========

https://hg.mozilla.org/integration/gaia-central/rev/da3a43fa2e36
Author: steveck-chung <schung@mozilla.com>
Desc: Merge pull request #11178 from steveck-chung/bug-895817

Bug 895817 - [SMS/MMS] Selecting a contact from facebook is not working. r=gnarf37

========

https://hg.mozilla.org/integration/gaia-central/rev/71fe21f9d44a
Author: Steve Chung <schung@mozilla.com>
Desc: Bug 895817 - [SMS/MMS] Selecting a contact from facebook is not working

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "39737621d1f3ca1609a397723cbbb9505285faa0", 
+    "revision": "da3a43fa2e36a21be66ff182a981b67c38e20067", 
     "repo_path": "/integration/gaia-central"
 }