Description of change
The error message returned for running juju switch without an argument was changed in https://github.com/juju/juju/pull/10885, but the test nw-unregister-controller still makes an assertion based on the old message.
This simply updates the expected message to what the error return is.
QA steps
Test nw-unregister-controller passes.
该提问来源于开源项目:juju/juju