g13: Require a confirmation before g13 is used for DM-Crypt.
* g13/g13-syshelp.c (g13_syshelp_i_know_what_i_am_doing): * g13/sh-dmcrypt.c (sh_dmcrypt_create_container): Call it. (sh_dmcrypt_mount_container): Call it.
- Signed-off-by: Werner Koch <wk@gnupg.org>