security: Allow reloading ValidationPolicyConfig / ValidatorConfig

Change-Id: Idba53c0b4e2cf645d3d0e6c76c57a1b54995462a
Refs: #4261
diff --git a/src/security/v2/certificate-cache.cpp b/src/security/v2/certificate-cache.cpp
index b9d15aa..be2b084 100644
--- a/src/security/v2/certificate-cache.cpp
+++ b/src/security/v2/certificate-cache.cpp
@@ -1,5 +1,5 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
-/**
+/*
  * Copyright (c) 2013-2017 Regents of the University of California.
  *
  * This file is part of ndn-cxx library (NDN C++ library with eXperimental eXtensions).
@@ -58,6 +58,12 @@
   m_certs.insert(Entry(cert, removalTime));
 }
 
+void
+CertificateCache::clear()
+{
+  m_certs.clear();
+}
+
 const Certificate*
 CertificateCache::find(const Name& certPrefix) const
 {