config.mak.uname: set NO_APPLE_COMMON_CRYPTO on older systems

Older MacOS systems prior to 10.5 do not have the CommonCrypto
support Git uses so set NO_APPLE_COMMON_CRYPTO on those systems.

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

config.mak.uname

@@ -88,6 +88,7 @@ ifeq ($(uname_S),Darwin)
 	NEEDS_LIBICONV = YesPlease
 	ifeq ($(shell expr "$(uname_R)" : '[15678]\.'),2)
 		OLD_ICONV = UnfortunatelyYes
+		NO_APPLE_COMMON_CRYPTO = YesPlease
 	endif
 	ifeq ($(shell expr "$(uname_R)" : '[15]\.'),2)
 		NO_STRLCPY = YesPlease