vdsm: sslTests updated to use sslutils

sslTests used ssl code from SecureXMLRPCServer which was moved to new
module.

Change-Id: I630acc8f2e29764c35a77f45ab6f08eef46433ad
Signed-off-by: pkliczewski <piotr.kliczewski@gmail.com>
Reviewed-on: http://gerrit.ovirt.org/28807
Reviewed-by: Nir Soffer <nsoffer@redhat.com>
Reviewed-by: Dan Kenigsberg <danken@redhat.com>