introduce oer constraint code
diff --git a/skeletons/NULL.c b/skeletons/NULL.c
index d966827..03090d1 100644
--- a/skeletons/NULL.c
+++ b/skeletons/NULL.c
@@ -42,6 +42,7 @@
 	sizeof(asn_DEF_NULL_tags) / sizeof(asn_DEF_NULL_tags[0]),
 	asn_DEF_NULL_tags,	/* Same as above */
 	sizeof(asn_DEF_NULL_tags) / sizeof(asn_DEF_NULL_tags[0]),
+	0,	/* No OER visible constraints */
 	0,	/* No PER visible constraints */
 	0, 0,	/* No members */
 	0	/* No specifics */