Reduce namespace nesting (ndn::ndncert -> ndncert)

Change-Id: I5b69a2c3673cccdf07ea0ba3a0e7181894328f47
diff --git a/src/detail/profile-storage.hpp b/src/detail/profile-storage.hpp
index 5955f15..3df6407 100644
--- a/src/detail/profile-storage.hpp
+++ b/src/detail/profile-storage.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
- * Copyright (c) 2017-2020, Regents of the University of California.
+/*
+ * Copyright (c) 2017-2021, Regents of the University of California.
  *
  * This file is part of ndncert, a certificate management system based on NDN.
  *
@@ -23,7 +23,6 @@
 
 #include "detail/ca-profile.hpp"
 
-namespace ndn {
 namespace ndncert {
 namespace requester {
 
@@ -69,6 +68,5 @@
 
 } // namespace requester
 } // namespace ndncert
-} // namespace ndn
 
 #endif // NDNCERT_DETAIL_PROFILE_STORAGE_HPP