Make fail2ban's apache-auth work with auth_digest

By default fail2ban's apache-auth only works with auth_basic. To make it work with auth_digest:

vi /etc/fail2ban/filter.d/apache-auth.conf
        delete old failregex line
        failregex = [[]client <HOST>[]] .* user .* authentication failure
            [[]client <HOST>[]] .* user .* not found
            [[]client <HOST>[]] .* user .* password mismatch

Source:
http://www.fail2ban.org/wiki/index.php/Fail2ban:Community_Portal#Modify_.22apache-auth.conf.22_to_allow_banning_on_server_using_digest_authentication