npl: npls more conveniently instantiable

NPLs can now be instantiated using brace-init lists, as well as by passing
any iterator-capable container.

refs: #4345

Change-Id: Ib43373d5899d0ac14861027c34431fa928eec191
diff --git a/tests/test-name-prefix-table.cpp b/tests/test-name-prefix-table.cpp
index 474585c..5322cb7 100644
--- a/tests/test-name-prefix-table.cpp
+++ b/tests/test-name-prefix-table.cpp
@@ -89,8 +89,7 @@
   // BUPT Name LSA
   ndn::Name buptAdvertisedName("/ndn/cn/edu/bupt");
 
-  NamePrefixList buptNames;
-  buptNames.insert(buptAdvertisedName);
+  NamePrefixList buptNames{buptAdvertisedName};
 
   NameLsa buptNameLsa(buptRouterName, 1, ndn::time::system_clock::now(),
                       buptNames);