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

========

https://hg.mozilla.org/integration/gaia-central/rev/f5dc746df1ae
Author: Julien Wajsberg <felash@gmail.com>
Desc: Revert "Bug 920546 - [Messages] Short-term fixes for the recipient panel r=julienw"

This reverts commit 7c5b6e746b800b3747c3be6eae67ad3948891497.

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "7864248beea958183b9d9d8df7dc8b7cefc42cee", 
+    "revision": "f5dc746df1ae66d610b4cc9c01475071b9cab795", 
     "repo_path": "/integration/gaia-central"
 }