PARIS — Speaking with an air of resignation, Andre Villas-Boas accepted his time as Marseille coach might soon be up following another home defeat. The 1-0 loss to Lens in the French league on Wednesday, where he was tactically outwitted by a novice coach, came after an abject team performance last weekend in a 2-1 home reverse to Nimes. Villas-Boas did not even try to defend himself. “If I’m the one who is responsible, which I am, then I am at the disposal of the directors,” he said calmly. “I don’t have a problem with that. I’m not here to become an obstacle.