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

========

https://hg.mozilla.org/integration/gaia-central/rev/6b934ba8010f
Author: Julien Wajsberg <felash@gmail.com>
Desc: Merge pull request #29217 from julienw/1142540-contact-promises

Bug 1142540 - move contacts.js to promises.

========

https://hg.mozilla.org/integration/gaia-central/rev/582bad3c53f0
Author: Julien Wajsberg <felash@gmail.com>
Desc: Bug 1142540 - move contacts.js to promises. r=azasypkin

b2g/config/gaia.json

@@ -1,9 +1,9 @@
 {
     "git": {
-        "git_revision": "d7599cdbc23be867091063b2bc722adc0a474709", 
+        "git_revision": "43f67fb074c326286bdb15b31749b0905d427558", 
         "remote": "https://git.mozilla.org/releases/gaia.git", 
         "branch": ""
     }, 
-    "revision": "9c5fe08f5e32c573e8b7c2c4a63f7a004fe88a1b", 
+    "revision": "6b934ba8010f97da833911efa89b805454a6f0fb", 
     "repo_path": "integration/gaia-central"
 }