mgmt: Fix compilation error with new version of ndn-cxx library

Change-Id: Ibdcbfef6fc7e2ab6c5d06353f372a894b19d7e34
Refs: #3083
diff --git a/src/mgmt/management-tool.cpp b/src/mgmt/management-tool.cpp
index ed7af04..62b57af 100644
--- a/src/mgmt/management-tool.cpp
+++ b/src/mgmt/management-tool.cpp
@@ -623,8 +623,8 @@
     return false;
   }
 
-  if (!m_keyChain.doesKeyExistInTpm(keyName, KEY_CLASS_PRIVATE)) {
-    NDNS_LOG_WARN("Private key: " << keyName.toUri() << " is not presented in KeyChain");
+  if (!m_keyChain.doesKeyExistInTpm(keyName, KeyClass::PRIVATE)) {
+    NDNS_LOG_WARN("Private key: " << keyName.toUri() << " is not present in KeyChain");
     return false;
   }