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

========

https://hg.mozilla.org/integration/gaia-central/rev/591b714a4728
Author: Cristian Rodriguez <crdlc@tid.es>
Desc: Merge pull request #15804 from crdlc/bug-964724

Bug 964724 - Hide regular Offline Error Screen When Connectivity Resumes...

========

https://hg.mozilla.org/integration/gaia-central/rev/815d055bbcc1
Author: crdlc <crdlc@tid.es>
Desc: Bug 964724 - Hide regular Offline Error Screen When Connectivity Resumes - App Foreground and Background

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "95abe5f17339d568b222c31e3e8389f05cc91fd2", 
+    "revision": "591b714a4728100c03278f8237f360a7b5082a56", 
     "repo_path": "/integration/gaia-central"
 }