Use https protocol by default

[nya1]

Hello,
I noticed that all requests are not using https by default, this can cause issues on some browsers served on https because of mixed content.

Code reference:
https://github.com/woubuc/node-updown/blob/master/src/utils/url.ts#L21

[woubuc]

Thanks for reporting this. I hadn't realised that I put the default on http, it should most definitely be https!