(s)-3-Biphenyl-4-yl-2-({(s)-3-[4-(3,4-dichloro-benzyloxy)-phenyl]-2,3,6,7,8,9-hexahydro-[1,4]dioxino-[2,3-g]isoquinoline-8-carbonyl}-amino)-propionic acid methyl ester hydrochloride salt