lp: wrap Data in PrefixAnnouncement field

Change-Id: I47e33518cec60a29d4518433245f22283b96b747
refs: 4280
diff --git a/src/lp/field-decl.hpp b/src/lp/field-decl.hpp
index 755f595..fa584af 100644
--- a/src/lp/field-decl.hpp
+++ b/src/lp/field-decl.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2013-2017 Regents of the University of California.
+ * Copyright (c) 2013-2018 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -90,7 +90,7 @@
 struct EncodeHelper
 {
   static
-  BOOST_CONCEPT_REQUIRES(((WireEncodable<T>)), (size_t))
+  BOOST_CONCEPT_REQUIRES(((WireEncodableWithEncodingBuffer<T>)), (size_t))
   encode(EncodingImpl<TAG>& encoder, const T& value)
   {
     return value.wireEncode(encoder);