CLEANUP: da: use the build options list to report it

This removes one #ifdef from haproxy.c.
diff --git a/src/da.c b/src/da.c
index d15e573..1dd148f 100644
--- a/src/da.c
+++ b/src/da.c
@@ -364,4 +364,5 @@
 	sample_register_fetches(&fetch_kws);
 	sample_register_convs(&conv_kws);
 	cfg_register_keywords(&dacfg_kws);
+	hap_register_build_opts("Built with DeviceAtlas support.", 0);
 }