if an unknown proxy connects to the zabbix server, sometimes really uninformative messages are printed :

Invalid discovery data. Can't find pair with name "clock"
Invalid auto registration data. Can't find pair with name "clock"
Received invalid host availability data. Can't find pair with name "data"
cannot find "data" pair

it would be great if these could provide more useful information, and preferably - ip address that data is being received from.

related to ZBXNEXT-377