s4/selftest: Modify samba4.blackbox.chgdcpass to use smbclient(s3)

s4/selftest: Modify samba4.blackbox.chgdcpass to use smbclient(s3)

Test was using smbclient4 but this fails when used in environments that
don't support SMB1. We use smbclient(s3) instead. There remains one
failure due to behaviour differences between the smbclients.

The behavioural changes are related not to SMB1/SMB2 but
commits d4ea637eb869e0c3540140b7ae04c2b483f7693c &
fce66b22ea312abb252fb9dc748b3adc6fbab49f

Perhaps we need to modify s3 smbclient in a similar way? This is however
something that deserves further discussion.

Move this failing part to a knownfail for the moment.

Also the corrosponding entry in skip_smb1_fail has been removed

Signed-off-by: Noel Power <noel.power@suse.com>
Reviewed-by: Ralph Boehme <slow@samba.org>