tests: namespace cleanup

Change-Id: I6b9ee82a4cb3b97c82ea111495ec07efddc8d825
diff --git a/tests/test-lsa-rule.cpp b/tests/test-lsa-rule.cpp
index eaebf12..87f915d 100644
--- a/tests/test-lsa-rule.cpp
+++ b/tests/test-lsa-rule.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2023,  The University of Memphis,
+ * Copyright (c) 2014-2024,  The University of Memphis,
  *                           Regents of the University of California,
  *                           Arizona Board of Regents.
  *
@@ -31,8 +31,7 @@
 #include <boost/property_tree/info_parser.hpp>
 #include <boost/property_tree/ptree.hpp>
 
-namespace nlsr {
-namespace test {
+namespace nlsr::tests {
 
 using namespace ndn;
 
@@ -156,5 +155,4 @@
 
 BOOST_AUTO_TEST_SUITE_END()
 
-} // namespace test
-} // namespace nlsr
+} // namespace nlsr::tests