address comments from Davide

Change-Id: I4450a345df616266270e0884c4a7c49994ebf54f
diff --git a/wscript b/wscript
index c5df199..e39459a 100644
--- a/wscript
+++ b/wscript
@@ -52,13 +52,13 @@
     # system has a different version of the ndncert library installed.
     conf.env.prepend_value('STLIBPATH', ['.'])
 
-    conf.define_cond('NDNCERT_HAVE_TESTS', conf.env.WITH_TESTS)
+    conf.define_cond('HAVE_TESTS', conf.env.WITH_TESTS)
     conf.define('SYSCONFDIR', conf.env.SYSCONFDIR)
     # The config header will contain all defines that were added using conf.define()
     # or conf.define_cond().  Everything that was added directly to conf.env.DEFINES
     # will not appear in the config header, but will instead be passed directly to the
     # compiler on the command line.
-    conf.write_config_header('src/ndncert-config.hpp')
+    conf.write_config_header('src/detail/ndncert-config.hpp', define_prefix='NDNCERT_')
 
     conf.define_cond('WITH_SYSTEMD', conf.options.with_systemd)