[Minor] Allow to register idempotent filters from Lua

src/lua/lua_config.c

@@ -1405,6 +1405,9 @@ lua_parse_symbol_flags (const gchar *str)
 		if (strstr (str, "nostat") != NULL) {
 			ret |= SYMBOL_TYPE_NOSTAT;
 		}
+		if (strstr (str, "idempotent") != NULL) {
+			ret |= SYMBOL_TYPE_IDEMPOTENT;
+		}
 	}
 
 	return ret;
@@ -1436,6 +1439,9 @@ lua_parse_symbol_type (const gchar *str)
 					ret = SYMBOL_TYPE_PREFILTER | SYMBOL_TYPE_GHOST;
 				} else if (g_ascii_strcasecmp (str, "postfilter") == 0) {
 					ret = SYMBOL_TYPE_POSTFILTER | SYMBOL_TYPE_GHOST;
+				} else if (g_ascii_strcasecmp (str, "idempotent") == 0) {
+					ret = SYMBOL_TYPE_POSTFILTER | SYMBOL_TYPE_GHOST |
+							SYMBOL_TYPE_IDEMPOTENT;
 				} else {
 					gint fl = 0;