Bumping gaia.json for 4 gaia revision(s) a=gaia-bump

========

https://hg.mozilla.org/integration/gaia-central/rev/b4e4e893a644
Author: Ryan VanderMeulen <rvandermeulen@mozilla.com>
Desc: Merge pull request #17148 from flodolo/bug942582_emergencycalltext

Bug 942582 - [System] Improve string for emergency call back mode

========

https://hg.mozilla.org/integration/gaia-central/rev/267f5d409238
Author: Francesco Lodolo (:flod) <flod@lodolo.net>
Desc: Bug 942582 - [System] Improve string for emergency call back mode

Updated string by :matej

========

https://hg.mozilla.org/integration/gaia-central/rev/3cc816903cce
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 983117 - Disable intermittent failing test, Browser Bookmarks > Add bookmark

========

https://hg.mozilla.org/integration/gaia-central/rev/69ca20a7fbcc
Author: Kevin Grandon <kevingrandon@yahoo.com>
Desc: Bug 983117 - Disable intermittent failing test, Browser Bookmarks > Edit bookmark

b2g/config/gaia.json

@@ -4,6 +4,6 @@
         "branch": "", 
         "revision": ""
     }, 
-    "revision": "40471bfa7ae54f5161357566997095b7e41a99ab", 
+    "revision": "b4e4e893a644748898a3a23d25e619789dbe02cd", 
     "repo_path": "/integration/gaia-central"
 }