mgr/dashboard: Editing RGW bucket fails because of name is already in use
When editing an RGW bucket, the only field that can be changed is `Owner`.
When the owner is changed to `-- Select a user --` and the `Edit Bucket` button is clicked, the form says that the owner is a required field. By ignoring that and re-clicking `Edit Bucket`, the form adds an additional error, saying that `The chosen name is already in use` below the `Name` field, although the name can not be changed. As far as I can tell, the latter validation error can not be fixed without reloading the page.