When a sequence title was unavailable for a user (e.g. before starting a timed exam), the `None` value was displayed in course breadcrumbs. This hides it in such cases and ensures that a trailing breadcrumb separator is not displayed.
When a sequence title was unavailable for a user (e.g. before starting a timed exam), the `None` value was displayed in course breadcrumbs. This hides it in such cases and ensures that a trailing breadcrumb separator is not displayed.