Update changelog

CHANGES.rst

-Changes in synapse v0.10.0-r2 (2015-09-10)
+Changes in synapse v0.10.0-r2 (2015-09-16)
 ==========================================
 
 * Fix bug where we always fetched remote server signing keys instead of using
   ones in our cache.
 * Fix adding threepids to an existing account.
+* Fix bug with invinting over federation where remote server was already in
+  the room. (PR #281, SYN-392)
 
 Changes in synapse v0.10.0-r1 (2015-09-08)
 ==========================================