Adapting to TLV-specific ndn-cpp

Change-Id: I5f39f38156221fc978db5048c1ff4a3bbb0c17d9
diff --git a/src/profile-data.h b/src/profile-data.h
index dbe4ca5..92353a1 100644
--- a/src/profile-data.h
+++ b/src/profile-data.h
@@ -17,6 +17,8 @@
 class ProfileData : public ndn::Data
 {
 public:
+  struct Error : public ndn::Data::Error { Error(const std::string &what) : ndn::Data::Error(what) {} };
+
   ProfileData();
 
   ProfileData(const Profile& profile);