Simplify some code with Boost.Operators

Change-Id: Ic873bcbaf6be00d5c35601cfc8090df534d815ee
diff --git a/daemon/table/fib.cpp b/daemon/table/fib.cpp
index f30b976..87e180a 100644
--- a/daemon/table/fib.cpp
+++ b/daemon/table/fib.cpp
@@ -1,6 +1,6 @@
 /* -*- Mode:C++; c-file-style:"gnu"; indent-tabs-mode:nil; -*- */
 /*
- * Copyright (c) 2014-2022,  Regents of the University of California,
+ * Copyright (c) 2014-2023,  Regents of the University of California,
  *                           Arizona Board of Regents,
  *                           Colorado State University,
  *                           University Pierre & Marie Curie, Sorbonne University,
@@ -27,12 +27,8 @@
 #include "pit-entry.hpp"
 #include "measurements-entry.hpp"
 
-#include <ndn-cxx/util/concepts.hpp>
-
 namespace nfd::fib {
 
-NDN_CXX_ASSERT_FORWARD_ITERATOR(Fib::const_iterator);
-
 const unique_ptr<Entry> Fib::s_emptyEntry = make_unique<Entry>(Name());
 
 static inline bool