If audit log is turned on then Pause Queue doesn't work and causes java.lang.NullPointerException.
Steps to reproduce:
1. Start ActiveMQ normally with audit log turned on: ./activemq start -Dorg.apache.activemq.audit=true
2. Create a Queue normarlly: http://127.0.0.1:8161/admin/ > Queues > Enter Queue Name > Create
3. Pause newly created queue: Click on `Pause`.
- Queue is paused normally.
- Error in web console:
Error! Exception occurred while processing this request, check the log for more information!
- Error in the `activemq.log`: