bug#50507: New function in Emacs GnuTLS implementation

[Nikolaos Chatzikonstantinou <nchatz314@gmail.com>]

> On 30 Dec 2022, at 10:45 PM, Mattias Engdegård <mattias.engdegard@gmail.com> wrote:
> 
> After e9983b1b63, the build of master fails on emba.gnu.org which perhaps uses a slightly older gnutls. Errors below.
> 
> CC       gnutls.o
> gnutls.c: In function 'key_file2_aux':
> gnutls.c:1829:8: error: 'GNUTLS_PKCS_PBES2_GOST_TC26Z' undeclared (first use in this function)
>  rv |= GNUTLS_PKCS_PBES2_GOST_TC26Z;
>        ^~~~~~~~~~~~~~~~~~~~~~~~~~~~
> gnutls.c:1829:8: note: each undeclared identifier is reported only once for each function it appears in
> gnutls.c:1831:8: error: 'GNUTLS_PKCS_PBES2_GOST_CPA' undeclared (first use in this function)
>  rv |= GNUTLS_PKCS_PBES2_GOST_CPA;
>        ^~~~~~~~~~~~~~~~~~~~~~~~~~
> gnutls.c:1833:8: error: 'GNUTLS_PKCS_PBES2_GOST_CPB' undeclared (first use in this function)
>  rv |= GNUTLS_PKCS_PBES2_GOST_CPB;
>        ^~~~~~~~~~~~~~~~~~~~~~~~~~
> gnutls.c:1835:8: error: 'GNUTLS_PKCS_PBES2_GOST_CPC' undeclared (first use in this function)
>  rv |= GNUTLS_PKCS_PBES2_GOST_CPC;
>        ^~~~~~~~~~~~~~~~~~~~~~~~~~
> gnutls.c:1837:8: error: 'GNUTLS_PKCS_PBES2_GOST_CPD' undeclared (first use in this function)
>  rv |= GNUTLS_PKCS_PBES2_GOST_CPD;
>        ^~~~~~~~~~~~~~~~~~~~~~~~~~
> 

I can work on this tomorrow and fix it. I think it needs preprocessor guards on the version.

Regards,
Nikolaos Chatzikonstantinou