scd: Use the correct gpg for the v1.0 OpenPGP card hack.
* scd/app-openpgp.c (get_public_key): Use gnupg_module_name instead of just "gpg".
There is no bug report regarding this and it would be very unlikely
but we should always use the gpg belonging to our code.
- Signed-off-by: Werner Koch <email@example.com>