chunks+ping: don't pass Scheduler to ScopedEventId

It's no longer necessary.

refs #4698

Change-Id: I17ff7362bc46686057fa0df203c6b745e013b1d3
diff --git a/core/common.hpp b/core/common.hpp
index 8e8c1db..4e76a6b 100644
--- a/core/common.hpp
+++ b/core/common.hpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2018,  Regents of the University of California,
+ * Copyright (c) 2014-2019,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -66,7 +66,6 @@
 #include <ndn-cxx/security/key-chain.hpp>
 #include <ndn-cxx/util/backports.hpp>
 #include <ndn-cxx/util/scheduler.hpp>
-#include <ndn-cxx/util/scheduler-scoped-event-id.hpp>
 #include <ndn-cxx/util/signal.hpp>
 #include <ndn-cxx/util/time.hpp>