[master] Update change log entry for 3799

ChangeLog

@@ -2,7 +2,7 @@
 	Per IPv6 subnet statistics (subnet[id].assigned-nas, 
 	subnet[id].total-nas, subnet[id].assigned-pds, and subnet[id].total-pds)
 	has been implemented.
-	(Trac #3799, git TBD)
+	(Trac #3799, git 4aa4808268bbc54290578f60ba60ed33cf344712)
 
 964.	[doc]		tomek
 	User's Guide and Developer's Guide updated with statistics and