s3-auth: make_new_system_info_session() now does not query nss

s3-auth: make_new_system_info_session() now does not query nss

This is important in some situations where these queries might be
costly LDAP queries and is just not required for the system token.
This is because the system token should be just the NT
AUTHORITY\SYSTEM user and just enough unix info to allow the token to
be used.

Andrew Bartlett

Signed-off-by: Andreas Schneider <asn@samba.org>
Autobuild-User(master): Andreas Schneider <asn@cryptomilk.org>
Autobuild-Date(master): Tue Jun 19 13:34:28 CEST 2012 on sn-devel-104