+ return false; // Simply return false for a meaningful error message on screen, see the comment below.
+ // die($res->getMessage()); // old_password() function is removed in MySQL 5.7.5.
+ // We are getting a confusing "MDB2 Error: not found" in this case if we die.
+ // TODO: perhaps it's time to simplify things and remove handling of old passwords completely.
+ // HOWEVER: some users apparently never change their passwords. When I tried removing OLD_PASSWORDS
+ // support in November 2018, there were login issues with such users.