A list of host/port pairs to use for establishing the initial connection to
the Kafka cluster used for licensing. All servers in the cluster will be
discovered from the initial connection. This list should be in the following
form:
host1:port1,host2:port2,...
Since the servers are used for the initial connection to discover the full
cluster membership (which may change dynamically), the previous list does not
need to contain the full set of servers–you may want more than one, though, in
case a server is down.