face: support runtime MTU changes on Ethernet faces

refs #3257

Change-Id: I160fe444b889b8f7be19022a2bd52bbc9f7a21aa
diff --git a/daemon/face/ethernet-transport.cpp b/daemon/face/ethernet-transport.cpp
index 6b419bf..01e175b 100644
--- a/daemon/face/ethernet-transport.cpp
+++ b/daemon/face/ethernet-transport.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2019,  Regents of the University of California,
+ * Copyright (c) 2014-2020,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -58,11 +58,16 @@
     NDN_THROW_NESTED(Error(e.what()));
   }
 
-  m_netifStateConn = localEndpoint.onStateChanged.connect(
-    [=] (ndn::net::InterfaceState, ndn::net::InterfaceState newState) {
+  m_netifStateChangedConn = localEndpoint.onStateChanged.connect(
+    [this] (ndn::net::InterfaceState, ndn::net::InterfaceState newState) {
       handleNetifStateChange(newState);
     });
 
+  m_netifMtuChangedConn = localEndpoint.onMtuChanged.connect(
+    [this] (uint32_t, uint32_t mtu) {
+      setMtu(mtu);
+    });
+
   asyncRead();
 }