face: replace isOnDemand with FacePersistency

Change-Id: Ie6995b2d03bbb90faad158de2b055f72dd9ba73d
Refs: #2989
diff --git a/daemon/face/websocket-face.cpp b/daemon/face/websocket-face.cpp
index 4c781c3..3b94e6e 100644
--- a/daemon/face/websocket-face.cpp
+++ b/daemon/face/websocket-face.cpp
@@ -38,7 +38,7 @@
   , m_closed(false)
 {
   NFD_LOG_FACE_INFO("Creating face");
-  this->setOnDemand(true);
+  this->setPersistency(ndn::nfd::FACE_PERSISTENCY_ON_DEMAND);
 }
 
 void