Add midding virtual destructor.

git-svn-id: http://subversion.jackaudio.org/jack/jack2/trunk/jackmp@4711 0c269be4-1314-0410-8aa9-9f06e86f4224

common/JackRequestDecoder.h

@@ -33,6 +33,9 @@ struct JackClientHandlerInterface {
 
     virtual void ClientAdd(detail::JackChannelTransactionInterface* socket, JackClientOpenRequest* req, JackClientOpenResult* res) = 0;
     virtual void ClientRemove(detail::JackChannelTransactionInterface* socket, int refnum) = 0;
+    
+    virtual ~JackClientHandlerInterface()
+    {}
 
 };