internals_st::send_cert_req too small

[Nicolai Stange]

Hi all,

in `gnutls_int.h', we have
--8<---------------cut here---------------start------------->8---
unsigned send_cert_req:1;
--8<---------------cut here---------------end--------------->8---
i.e. its one single bit wide.

According to the definition of `gnutls_certificate_request_t' in
`gnutls.h', `send_cert_req' must be big enough to hold the the
enumerated values 0, 1 and 2.

On my platform (x86_64), gcc generates code that will silently set
`send_cert_req' to zero if `gnutls_certificate_server_set_request()'
is invoked with a req-value of `GNUTLS_CERT_REQUIRE' (== 2).
This results in clients not sending any certificate at all.

Regards,

Nicolai