Add RS-60 in release doc

As the issue of RS-60, we should add it in our release doc (VM page).
Basically if users pause with saving the machine state and restart VM, they may see some error due to RS being unable to find any registered workers:
Exception in thread "main" java.io.IOException: com.cloudera.recordservice.core.RecordServiceException: TRecordServiceException(code:INVALID_REQUEST, message:Worker membership is empty. Please ensure all RecordService Worker nodes are running.)

In this case, they can checkout if the membership is 0 in http://quickstart.cloudera:11050/membership, and they can fix it via restarting RecordService with the following command in VM:
sudo service recordservice-server restart