enforsed compilation with -W -Werror

diff --git a/skeletons/NumericString.c b/skeletons/NumericString.c
index a007496..ba58923 100644
--- a/skeletons/NumericString.c
+++ b/skeletons/NumericString.c
@@ -23,6 +23,7 @@
 	  / sizeof(asn1_DEF_NumericString_tags[0]),
 	1,	/* Single UNIVERSAL tag may be implicitly overriden */
 	-1,	/* Both ways are fine */
+	0	/* No specifics */
 };
 
 int