* syscalls.cc (seteuid): Set environment variables USERNAME and

    * syscalls.cc (seteuid): Set environment variables USERNAME and
        USERDOMAIN before impersonation to workaround a LookupAccountSid()
        misbehaviour.
        * uinfo.cc (internal_getlogin): Revert most of the previous change.
        Don't set environment variables USERNAME and USERDOMAIN. That's
        the job of seteuid() now. Try to get logon server from Lsa
        only if logon server isn't already known.