Cannot use an S3 compatible Server like Ceph Radosgw

Consider use host_base parameter of s3cfg file when initalize s3.Client.

I hardcode this to suit my case :
```node
function setup(secretAccessKey, accessKeyId) {
var maxSockets = parseInt(args['max-sockets'], 10);
http.globalAgent.maxSockets = maxSockets;
https.globalAgent.maxSockets = maxSockets;
client = s3.createClient({
s3Options: {
accessKeyId: accessKeyId,
secretAccessKey: secretAccessKey,
sslEnabled: !args.insecure,
endpoint: 'cephgw.my.com',
region: args.region,
},
});
var cmd = args._.shift();
var fn = fns[cmd];
if (!fn) fn = cmdHelp;
fn();
}
```