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

Truncated some number of revisions since the previous bump.

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https://hg.mozilla.org/integration/gaia-central/rev/8625b71fabf9
Author: James Lal <james@lightsofapollo.com>
Desc: Merge pull request #10309 from lightsofapollo/bug-810007-disallow-zero-length-events

Bug 810007 - Disallow zero length events during event creation

========

https://hg.mozilla.org/integration/gaia-central/rev/0dd20d6fb26e
Author: James Lal <james@lightsofapollo.com>
Desc: Bug 810007 - Disallow zero length events during event creation

b2g/config/gaia.json

@@ -1,4 +1,4 @@
 {
-    "revision": "c18a9987518a11d34217823633aace14f0384322", 
+    "revision": "8625b71fabf934859a64685bb8e89e463ca3f349", 
     "repo_path": "/integration/gaia-central"
 }