Allow ClientConfiguration proxy settings to be used with -Dcom.amazonaws.sdk.disableCertChecking

If you try to proxy any of the existing client objects using a ClientConfiguration such as
```Java
        ClientConfiguration config = new ClientConfiguration();
        config.setProxyHost("localhost");
        config.setProxyPort(8080);

        AmazonS3 s3 = new AmazonS3Client(new ClasspathPropertiesFileCredentialsProvider(), config);
```

and also pass ```-Dcom.amazonaws.sdk.disableCertChecking=treu``` all of the connections will fail with ``Socket not connected``` messages.

This patch corrects the ```TrustingSocketFactory.createLayeredSocket``` method to use the passed in Socket.