Modify BaseDNSBLClient._get_item_data
Modify BaseDNSBLClient._get_item_data

The new implementation shifts from using oudated query method
of each dnsbl service to calling their get_classification method.

The yielded value does not contain host, dnsbl service object and return code anymore,
only source identifier and classification of given host, if it's listed.

piotr-rusin/spam-lists