salt-cloud: ec2 cloud provider fix issue of windows minion deployment

In a continue to the thread below
https://groups.google.com/forum/#!searchin/salt-users/salt-cloud$20windows/salt-users/Qm9jqCjcwh8/qHmf2FL7W9cJ

when a windows minion is deployed there is no need to check for ssh_user authentication
checking for port 445 is done later in the deploy_windows function

I checked this on salt-cloud 0.8.11 & salt 0.17.2 with the following changes
note that here `get_config_value()` is used instead of `get_cloud_config_value()`
```
1255,1259c1255
<     if config.get_config_value('win_installer', vm_, __opts__):
<         username = config.get_config_value(
<                 'win_username', vm_, __opts__, default='Administrator'
<             )
<     elif saltcloud.utils.wait_for_port(ip_address, timeout=ssh_connect_timeout):
---
>     if saltcloud.utils.wait_for_port(ip_address, timeout=ssh_connect_timeout):
```