We watch the service owner so that when it dies without finishing the job we communicate an error to the user.
When the job is stopped, the job is "done" and we don't need to watch the service anymore.

• Started a copy, finished it, quit Dolphin: no longer got a "job unregistered" message
• Started a copy, killed Dolphin: got a "application closed unexpectedly" job error
• Started a copy, finished it, started a second copy, killed Dolphin, still got the error message