gpg: Fix leftover unprotected card backup key.
* agent/command.c (cmd_learn): Add option --reallyforce. * agent/findkey.c (agent_write_private_key): Implement reallyforce. Also add arg reallyforce and pass it along the call chain. * g10/call-agent.c (agent_scd_learn): Pass --reallyforce with a special force value. * g10/keygen.c (card_store_key_with_backup): Use that force value.
This was a regression in 2.2.42. We took the easy path to fix it by
getting the behaviour back to what we did prior to 2.2.42. With GnuPG
2.4.4 we use an entire different and safer approach by introducing an
ephemeral private key store.
- GnuPG-bug-id: T6944