Lazy configuration may result in two iframes when two requests are sent directly after each other

[timmolendijk]

var connection = new easyXDM.Rpc({
        remote: 'http://api.nouncy.eu/provider',
        lazy: true  // <-- the culprit
    }, {
        remote: {
            xhr: {}
        }
    });

connection.xhr("mock");
connection.xhr("mock");

This can lead to two iframes being created.

See a live demo here.