fixed error when using ssl transport with basic auth and without a cert file

When attempting to use the ssl transport without the new cert feature (basic auth over ssl), the following error occurs:
```
File "/devel/lib/pywinrm/winrm/transport.py", line 130, in _setup_opener
    super(HttpSSL, self)._setup_opener(message)
NameError: global name 'message' is not defined
```
This patch fixes this error and has been tested for SSL using basic auth.