ndn-cxx+build: Enable ndnSIM-specific ndn::Face implementation

Change-Id: I7b79425243114e7454bd81bd7b19ce22ff048f2e
Refs: #2370, #3119
diff --git a/model/ndn-l3-protocol.cpp b/model/ndn-l3-protocol.cpp
index ad9c0d7..3cbda38 100644
--- a/model/ndn-l3-protocol.cpp
+++ b/model/ndn-l3-protocol.cpp
@@ -214,7 +214,7 @@
 void
 L3Protocol::initializeManagement()
 {
-  auto keyChain = std::ref(StackHelper::getKeyChain());
+  auto& keyChain = StackHelper::getKeyChain();
   auto& forwarder = m_impl->m_forwarder;
   using namespace nfd;