fixed some of the TLS problems

fixed some of the TLS problems

This fixes two things in the TLS support for Samba4. The first is to
use a somewhat more correct hostname instead of 'Samba' when
generating the test certificates. That allows TLS test clients (such
as gnutls-cli) to connect to Samba4 using auto-generated certificates.

The second fix is to add a call to gcry_control() to tell gcrypt to
use /dev/urandom instead of /dev/random (on systems that support
that). That means that test certificate generation is now very fast,
which was previously an impediment to putting the TLS tests on the
build farm.