ActiveMQ webconsole breaks when supressMBean is used

AMQ-5656 which included the suppressMBean function broke the web console that comes with ActiveMQ. The proxied calls to ManagedRegionBroker will obtain objects that are not registered with the MBean server and thus the web console breaks with invalid JSP when executed, which ultimately is caused by javax.management.InstanceNotFoundException. The fix for this is to have the web calls filter out lists that contain any non-MBeans.