signature: Small API fixes

Change-Id: I1718dd5bdf702151e8125801a8f1dfc23cb680e4
diff --git a/src/signature-info.cpp b/src/signature-info.cpp
index d96aab3..821d5a7 100644
--- a/src/signature-info.cpp
+++ b/src/signature-info.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /**
- * Copyright (c) 2013-2015 Regents of the University of California.
+ * Copyright (c) 2013-2016 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
  *
@@ -119,6 +119,7 @@
 void
 SignatureInfo::appendTypeSpecificTlv(const Block& block)
 {
+  m_wire.reset();
   m_otherTlvs.push_back(block);
 }
 
@@ -215,7 +216,7 @@
 
   // Decode the rest of type-specific TLVs, if any
   while (it != m_wire.elements_end()) {
-    appendTypeSpecificTlv(*it);
+    m_otherTlvs.push_back(*it);
     it++;
   }
 }