scd: Error code map fix for older Yubikey.

* scd/iso7816.c (map_sw): Recognize 6A86.

Yubikey NEO does not support the YK4_GET_CAPA command (001D000000),
and it will be screwed up with the command.

Back-port-master-commit: 13bc0431ff1ce51246694208df611cc4561fb4b3

• GnuPG-bug-id: T5487
• Fixes-commit: ec56996029d95d4bd26e1badfe207232270c6247
• Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>