all: avoid usage of deprecated namespace ndn::Tlv

refs #2079

Change-Id: I32b7f10bcde1e70617950900d54f6ce0fb588ce9
diff --git a/src/repo-command-response.hpp b/src/repo-command-response.hpp
index 92b390b..79dc027 100644
--- a/src/repo-command-response.hpp
+++ b/src/repo-command-response.hpp
@@ -40,12 +40,12 @@
 class RepoCommandResponse
 {
 public:
-  class Error : public ndn::Tlv::Error
+  class Error : public ndn::tlv::Error
   {
   public:
     explicit
     Error(const std::string& what)
-      : ndn::Tlv::Error(what)
+      : ndn::tlv::Error(what)
     {
     }
   };