dsbl.org is no longer operating

roles/mailserver/templates/etc_postfix_main.cf.j2

@@ -102,7 +102,6 @@ smtpd_client_restrictions =
 # Postscreen
 postscreen_access_list = permit_mynetworks
 postscreen_dnsbl_sites =
-  multihop.dsbl.org*2
   sbl-xbl.spamhaus.org*2
   cbl.abuseat.org*2
   bl.spamcop.net*2