Drop unnecessary v2 namespace qualifications

Change-Id: I6358bac6860ca8f2e9cdbd00bb2a929e3af5b2da
diff --git a/tools/ndnsec/cert-gen.cpp b/tools/ndnsec/cert-gen.cpp
index 9aef677..9c11ca4 100644
--- a/tools/ndnsec/cert-gen.cpp
+++ b/tools/ndnsec/cert-gen.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).
  *
@@ -86,10 +86,10 @@
     return 0;
   }
 
-  security::v2::AdditionalDescription additionalDescription;
+  security::AdditionalDescription additionalDescription;
 
   for (const auto& info : infos) {
-    auto pos = info.find(" ");
+    auto pos = info.find(' ');
     if (pos == std::string::npos) {
       std::cerr << "ERROR: incorrectly formatted info block [" << info << "]" << std::endl;
       return 2;
@@ -122,9 +122,9 @@
     }
   }
 
-  security::v2::KeyChain keyChain;
+  KeyChain keyChain;
 
-  security::v2::Certificate certRequest;
+  security::Certificate certRequest;
   try {
     certRequest = loadCertificate(requestFile);
   }
@@ -143,7 +143,7 @@
     .append(issuerId)
     .appendVersion();
 
-  security::v2::Certificate cert;
+  security::Certificate cert;
   cert.setName(certName);
   cert.setContent(certRequest.getContent());
   // TODO: add ability to customize