support http proxy settings

[zshi-redhat]

sometimes, direct internet accessing is not possible, toad will be deployed with proper proxy settings.

[leifmadsen]

I'm working on adding traefik right now, hopefully that will simplify this request as well.

[leifmadsen]

So based on what you're trying to do, I was wrong on traefik helping you at all. Per our conversation last night, I think you might want to open a PR with the changes you made to tell the jenkins-cli.jar pull to skip using the HTTP proxy.