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

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https://hg.mozilla.org/integration/gaia-central/rev/c841891c0a3e
Author: autolander <bug.autolander@gmail.com>
Desc: Bug 1098289 - merge pull request #28029 from jrburke:bug1098289-email-request-sync to mozilla-b2g:master

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https://hg.mozilla.org/integration/gaia-central/rev/6a2f811a2f95
Author: jrburke <jrburke@gmail.com>
Desc: Bug 1098289 - Migrate Email to use navigator.sync (RequestSync) API (Phase1)

b2g/config/gaia.json

@@ -1,9 +1,9 @@
 {
     "git": {
-        "git_revision": "428e1971257b209c0383d25314da7d763fe2fbde", 
+        "git_revision": "2cee3b7bd197969cb19fdc75a52b7ad28b86a5bb", 
         "remote": "https://git.mozilla.org/releases/gaia.git", 
         "branch": ""
     }, 
-    "revision": "fa30aca9f337fed43cc644b022d8e457d24c3db8", 
+    "revision": "c841891c0a3e3697d9fc0b4470d1aacb74eee505", 
     "repo_path": "integration/gaia-central"
 }