'Remove, if subtitle content exists.'

def clear_sub_content(self, subs_id):

    filename = 'subs_{0}.srt.sjson'.format(subs_id)
    content_location = StaticContent.compute_location(self.course.id, filename)
    try:
        content = contentstore().find(content_location)
        contentstore().delete(content.location)
    except NotFoundError:
        pass
