fix changes file

changes/ticket23420

@@ -1,4 +1,4 @@
   o Minor bugfixes (hidden service v3):
     - Pad RENDEZVOUS cell up to the size of the legacy cell which is much
       bigger so the rendezvous point can't distinguish which hidden service
-      protocol is being used. Fixes ticket 23420.; bugfix on 0.3.2.1-alpha.
+      protocol is being used. Fixes bug 23420; bugfix on 0.3.2.1-alpha.