tools: switch to Face::getIoContext()

Change-Id: I6be4c682d62e1061af45052d2141b9e5b9e897c5
diff --git a/tools/nfd-autoreg.cpp b/tools/nfd-autoreg.cpp
index 292ccc8..58ce2c7 100644
--- a/tools/nfd-autoreg.cpp
+++ b/tools/nfd-autoreg.cpp
@@ -173,7 +173,7 @@
     m_faceMonitor.onNotification.connect([this] (const auto& notif) { onNotification(notif); });
     m_faceMonitor.start();
 
-    boost::asio::signal_set signalSet(m_face.getIoService(), SIGINT, SIGTERM);
+    boost::asio::signal_set signalSet(m_face.getIoContext(), SIGINT, SIGTERM);
     signalSet.async_wait([this] (auto&&...) { m_face.shutdown(); });
 
     m_face.processEvents();