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

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https://hg.mozilla.org/integration/gaia-central/rev/0b9f621ff0fc
Author: Amir Nissim <amirnissim@gmail.com>
Desc: Merge pull request #13181 from EverythingMe/919555-remove-appIndex

Bug 919555 - [e.me][perf] Remove app index duplicacy

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https://hg.mozilla.org/integration/gaia-central/rev/2a1dfb60ed7c
Author: Amir Nissim <amirnissim@gmail.com>
Desc: Bug 919555 - [e.me][perf] Remove app index duplicacy [r=ranbena, crdlc]

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "dc22cb96998eff0cab1f4efba87cb74aa1f98281", 
+    "revision": "0b9f621ff0fcca8f0aedcbf5dc032821d31a5af4", 
     "repo_path": "/integration/gaia-central"
 }