Fix compilation with Boost 1.65.0

Also sync default-compiler-flags.py with NFD

Change-Id: Ib39118567428e8fe2ac73f2b7cbd96fe1a9598b8
Refs: #4259, #4248
diff --git a/tools/chunks/catchunks/pipeline-interests-aimd.hpp b/tools/chunks/catchunks/pipeline-interests-aimd.hpp
index ec5bfce..aa19d3f 100644
--- a/tools/chunks/catchunks/pipeline-interests-aimd.hpp
+++ b/tools/chunks/catchunks/pipeline-interests-aimd.hpp
@@ -32,6 +32,7 @@
 #include "pipeline-interests.hpp"
 
 #include <queue>
+#include <unordered_map>
 
 namespace ndn {
 namespace chunks {