Drop unnecessary v2 namespace qualifications

Change-Id: I6358bac6860ca8f2e9cdbd00bb2a929e3af5b2da
diff --git a/tools/ndnsec/import.cpp b/tools/ndnsec/import.cpp
index 9dab73f..7e27bee 100644
--- a/tools/ndnsec/import.cpp
+++ b/tools/ndnsec/import.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2020 Regents of the University of California.
+ * Copyright (c) 2013-2021 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -72,7 +72,7 @@
     return 0;
   }
 
-  security::v2::KeyChain keyChain;
+  KeyChain keyChain;
 
   shared_ptr<security::SafeBag> safeBag;
   if (input == "-")