When trying to debug JMC-5397, the following flow happened

1. Start JMC
2. Start JDK9 build 156 process (like jconsole or jdb)
3. Try to create a recording against #2 process
4. JMC hangs, in FlightRecorderMBean#newRecording()
5. Restart JMC
6. No local JVMs are listed

This is caused by: during the population of local JVMs list, when trying to connect to process from #2, the call to com.sun.tools.attach.VirtualMachine.getProperties hangs, which prevents all of the other resources from being displayed

If the broken process is killed, the other local JVMs can be listed.

We should make sure that the rest of the local JVMs are listed even if one of them is broken.