contrib/libucl: Revert to old behavior of macros

Enable macros and includes by default as this is breaking package
building on HEAD. libucl 0.9.3 by default changed the behavior of
includes and macros. These were previously enabled but it switched to
disabled which breaks the package building in HEAD. This is a temporary
workaround for now to fix the package building specially for
releng/15.0. This might be reverted post EOL of 15.0 in the coming
months.

Reported by:	ivy
Fixes: abda442d92 ("contrib/libucl: Import libucl 0.9.3")
Tested by:	ivy
Approved by:	ivy, kevans
Differential Revision:	https://reviews.freebsd.org/D56294

contrib/libucl/lua/lua_ucl.c

@@ -656,7 +656,7 @@ lua_ucl_parser_init (lua_State *L)
 	 * files. Macros in the parser are very dangerous and should be used
 	 * for trusted data only.
 	 */
-	int flags = UCL_PARSER_NO_FILEVARS|UCL_PARSER_DISABLE_MACRO;
+	int flags = 0;
 
 	if (lua_gettop (L) >= 1) {
 		flags = lua_tonumber (L, 1);