[5275] Addressed review comments

doc/guide/ddns.xml

@@ -92,7 +92,7 @@
         In this way, DNS upates for both IPv4 and IPv6 can be managed under
         the same DHCID RR. Support for this does not yet exist in Kea but is
         called for in the ticket, http://kea.isc.org/ticket/4519, which we
-        hope to include in an upcoming release.
+        hope to include in a future release.
       </para>
     </section>
     </section>