CLOUDSTACK-6303 [Automation] [UI] Account creation hang in UI

Changes:
- Caused due to a MySql error during 'Project' account cleanup. The MySql error hits a deadlock bug in the MessageBus code that does not release the lock/decrement the counter Eventually all callers on the MessageBus end up waiting to enter
- This fixes the account cleanup MySql error.
CLOUDSTACK-6305: protect lock leaking from unhandled exception