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

========

https://hg.mozilla.org/integration/gaia-central/rev/4e20b480d24a
Author: Bebe <bebe@mozilla.ro>
Desc: Bug 918743 - xfail test_cards_view_with_three_apps due to bug 915138. r=atriff

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "4d91a52faace285fbc58284167609b9d23365259", 
+    "revision": "4e20b480d24a22a74436e8e619cf8b57acd61a4a", 
     "repo_path": "/integration/gaia-central"
 }