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

========

https://hg.mozilla.org/integration/gaia-central/rev/b70c6689d3de
Author: autolander <bug.autolander@gmail.com>
Desc: Bug 1136362 - merge pull request #28430 from asutherland:email-imap-logging to mozilla-b2g:master

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https://hg.mozilla.org/integration/gaia-central/rev/4f7e51dd54f3
Author: Andrew Sutherland <asutherland@asutherland.org>
Desc: Bug 1136362 - [email/IMAP] upgrade browserbox and imap-handler libs to get IMAP protocol logging. r=asuth

land https://github.com/mozilla-b2g/gaia-email-libs-and-more/pull/372

b2g/config/gaia.json

@@ -1,9 +1,9 @@
 {
     "git": {
-        "git_revision": "6dbdca8c2ffe8cca445e057fea8289731d132c88", 
+        "git_revision": "e4a5a54c0891a1cc964b2d94918408f2625c7aaa", 
         "remote": "https://git.mozilla.org/releases/gaia.git", 
         "branch": ""
     }, 
-    "revision": "e2d7e04ebc1b2f3b52dbaa8fc922babef22530dd", 
+    "revision": "b70c6689d3ded57b3dd70c77b42427e7b77b81ea", 
     "repo_path": "integration/gaia-central"
 }