'Can not find endpoint from printer' error message on printer having 'out' endpoint

[vachkov]

I get 'Can not find endpoint from printer', so I debugged and found that there is interface having endpoint with direction=out.

I have tested on windows, not sure for other platforms.

I believe the issue is in following code:
https://github.com/song940/node-escpos/blob/master/adapter/usb.js#L77
where iface.setAltSetting is called, this is async function and returns immediately, this leaves endpoints empty and leads to the explained error.