memcached1.3.2からdeleteは第２引数とらない

gistfile1.pl

use Sledge::Session::Memcached;
BEGIN {
    no warnings;
    *Sledge::Session::Memcached::_delete_me = sub {
        my $self = shift;
        my $ok = $self->{_dbh}->delete($self->{_sid});
        unless ($ok) {
            warn 'delete command fails';
        }
        $ok;
    };
}