gpg: Make --with-subkey-fingerprint the default.

* g10/gpg.c (oWithoutSubkeyFingerprint): New.
(opts): Add "without-subkey-fingerprint".
(main): Make --with-subkey-fingerprint the default.  Implementation
the without option.

Given that the default for the keyid format is none, the subkey
fingerprints are important to do anything with a subkey. Thus we make
the old option the default and provide a new option to revert it.