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

========

https://hg.mozilla.org/integration/gaia-central/rev/59dd11469f4b
Author: Ben Francis <ben@tola.me.uk>
Desc: Bug 968049 - Don't try to reload a null URL when reviving crashed tabs

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "6ec8b59d9a5833bcf21245988c7935454b184b4f", 
+    "revision": "59dd11469f4bb971d69dfad638f5af9df5124152", 
     "repo_path": "/integration/gaia-central"
 }