Alternative monitor plugin could be print of jmx url

This is related to follow-up on review of FR 1471.
The cuurent implementation of PrintMonitorRegistryClient.register prints
"This client may be monitored on host '"
+ hostName + "' port '" + jmxPort
+ "' (RMI callback on port '" + rmiPort + "')");
It cound be nicer if this was print of jmx url