face: downgrade "Creating transport" log message to DEBUG

FaceTable already logs at INFO level whenever a new face is added.

Change-Id: Id2905c8b6d42df8bfc4c43cc12d432d9ce180aae
diff --git a/daemon/face/multicast-udp-transport.cpp b/daemon/face/multicast-udp-transport.cpp
index ec50d7f..2c61527 100644
--- a/daemon/face/multicast-udp-transport.cpp
+++ b/daemon/face/multicast-udp-transport.cpp
@@ -68,7 +68,7 @@
     this->setSendQueueCapacity(sendBufferSizeOption.value());
   }
 
-  NFD_LOG_FACE_INFO("Creating transport");
+  NFD_LOG_FACE_DEBUG("Creating transport");
 }
 
 ssize_t