openpgp api changes

[Simon Josefsson]

Hi Nikos, I just noticed this commit:

http://git.savannah.gnu.org/gitweb/?p=gnutls.git;a=commitdiff;h=1eb501d0a85a742778e507ebfbb8f05a984559eb

The gnutls_openpgp_crt_get_auth_subkey function was part of GnuTLS
2.2.x, so changing it will trigger a shared library bump, and I want to
avoid that for 2.4.x.

Can you see any other way to solve this than introducing a new parameter
to the function?

If that's not the case, please add a new function instead of changing
one, perhaps as gnutls_openpgp_crt_get_auth_subkey2, which would takes
the flag parameter, and make the old gnutls_openpgp_crt_get_auth_subkey
function call that new function if possible.

/Simon