daemon: mark some classes and methods 'final'

As suggested by gcc's -Wsuggest-final-types and -Wsuggest-final-methods

Change-Id: I1622857ee53581efd0c6ce3fe93199c72202d817
diff --git a/daemon/mgmt/cs-manager.hpp b/daemon/mgmt/cs-manager.hpp
index 83db017..95fbffc 100644
--- a/daemon/mgmt/cs-manager.hpp
+++ b/daemon/mgmt/cs-manager.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2021,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -40,7 +40,7 @@
  * \brief Implements the CS Management of NFD Management Protocol.
  * \sa https://redmine.named-data.net/projects/nfd/wiki/CsMgmt
  */
-class CsManager : public ManagerBase
+class CsManager final : public ManagerBase
 {
 public:
   CsManager(cs::Cs& cs, const ForwarderCounters& fwCounters,