[master] Added ChangeLog entry for trac3841 (use remove() vs unlink())

ChangeLog

@@ -1,4 +1,8 @@
-Kea 0.9.2-beta released on June 30, 2015
+968.	[func]		fdupont
+	Changed all occurrences of unlink() to the more portable remove()
+	to avoid problems on operating systems where the former is not
+	available.
+	(Trac #3841, git xxx)
 
 967.	[doc]		tomek
 	Management API section added in the DHCPv6 chapter of the Kea