Adapt to ndn-cxx security changes

refs: #4090, #4195, #3828

Change-Id: Ie1bf11d604af12d3b26fba24054ed67fe735ae7c
diff --git a/wscript b/wscript
index e3e3b1e..01139df 100644
--- a/wscript
+++ b/wscript
@@ -21,7 +21,7 @@
 
 def configure(conf):
     conf.load(['compiler_c', 'compiler_cxx', 'gnu_dirs',
-               'default-compiler-flags', 'boost', 'pch', 'sanitizers', 'coverage',
+               'default-compiler-flags', 'boost', 'pch', 'coverage',
                'doxygen', 'sphinx_build'])
 
     conf.check_cfg(package='libndn-cxx', args=['--cflags', '--libs'],
@@ -35,6 +35,8 @@
 
     conf.check_boost(lib=boost_libs, mt=True)
 
+    conf.load('sanitizers')
+
     # If there happens to be a static library, waf will put the corresponding -L flags
     # before dynamic library flags.  This can result in compilation failure when the
     # system has a different version of the ChronoSync library installed.