rib: stop using the global scheduler

Change-Id: I0e205e2f1adf85be49b132b47791b27e4530697a
Refs: #4528
diff --git a/rib/service.hpp b/rib/service.hpp
index 135df58..0b06013 100644
--- a/rib/service.hpp
+++ b/rib/service.hpp
@@ -35,6 +35,7 @@
 #include <ndn-cxx/mgmt/nfd/controller.hpp>
 #include <ndn-cxx/security/key-chain.hpp>
 #include <ndn-cxx/transport/transport.hpp>
+#include <ndn-cxx/util/scheduler.hpp>
 
 namespace nfd {
 namespace rib {
@@ -110,6 +111,7 @@
 
   ndn::KeyChain& m_keyChain;
   ndn::Face m_face;
+  ndn::util::Scheduler m_scheduler;
   ndn::nfd::Controller m_nfdController;
 
   Rib m_rib;