connectors/rbd.py raises exception.BrickException with wrong named parameter

In rbd.py the exception.BrickException is raised with the named parameter msg but exception.BrickException named paramter is message.

This leeds to unconclusive error messages like:
...
packages/os_brick/initiator/connectors/rbd.py", line 85, in _check_or_get_keyring_contents
2020-02-18 11:55:27.962 24 ERROR oslo_messaging.rpc.server raise exception.BrickException(msg=msg)
2020-02-18 11:55:27.962 24 ERROR oslo_messaging.rpc.server BrickException: An unknown exception occurred.
...
Please find attached a patch file which solved this problem for me.

Thanks for your great work on openstack!

Take care,
Björn Puttmann