core: km_parse_avp_spec() update

- fallback to ser style of avp name in $avp(id) if 'id' has no ':' and
  there is no avp alias defined
- behavior was changed when I added support for K compatible avp aliases
  in pv module
- issue reported by Andrei Pelinscu-Onciul

usr_avp.c

@@ -1041,11 +1041,11 @@ int km_parse_avp_spec( str *name, int *type, int_str *avp_name)
 
 	p = (char*)memchr((void*)name->s, ':', name->len);
 	if (p==NULL) {
-		/* it's an avp alias */
-		return lookup_avp_galias( name, type, avp_name);
-	} else {
-		return parse_avp_name( name, type, avp_name, &index);
+		/* might be kamailio avp alias or ser avp name style */
+		if(lookup_avp_galias( name, type, avp_name)==0)
+			return 0; /* found */
 	}
+	return parse_avp_name( name, type, avp_name, &index);
 }