remove useless codes related to CERT_QUERY

Change-Id: I5c2b75d9f26116fabee628cffd54b0247a69646d
diff --git a/src/ndns-label.cpp b/src/ndns-label.cpp
index 9386452..747f13a 100644
--- a/src/ndns-label.cpp
+++ b/src/ndns-label.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2014-2016, Regents of the University of California.
+ * Copyright (c) 2014-2017, Regents of the University of California.
  *
  * This file is part of NDNS (Named Data Networking Domain Name Service).
  * See AUTHORS.md for complete list of NDNS authors and contributors.
@@ -36,8 +36,7 @@
   BOOST_ASSERT(name.size() > skip);
   BOOST_ASSERT(name.getPrefix(zone.size()) == zone);
 
-  BOOST_ASSERT(name.get(skip) == NDNS_ITERATIVE_QUERY ||
-               name.get(skip) == NDNS_CERT_QUERY);
+  BOOST_ASSERT(name.get(skip) == NDNS_ITERATIVE_QUERY);
 
   ++skip;
   return skip;