Update the url of HudsonArch-Remoting.pdf

[donhui]

• Make sure you are opening from a topic/feature/bugfix branch (right side) and not your master branch!
• Ensure that the pull request title represents the desired changelog entry
• Please describe what you did
• Link to relevant issues in GitHub or Jira
• Link to relevant pull requests, esp. upstream and downstream changes
• Ensure you have provided tests - that demonstrates feature works or fixes the issue

Update the url of HudsonArch-Remoting.pdf, because hudson-ci.org cannot be accessed.

[oleg-nenashev]

+1 for the update itself. At the same time the slidedeck is quite old. While still useful for the JNLP4-connect protocol and Jenkins RMI parts, it does not represent newer connection modes (websockets, Remoting over Apache Kafka). It also uses the deprecated terminology. Ideally we should replace the document by a more modern architecture overview.

I have an old https://speakerdeck.com/onenashev/day-of-jenkins-2017-dealing-with-agent-connectivity-issues slidedeck with some architecture references. We also made a "Scaling Network Connections from the Jenkins controller" talk together with @jglick with some insight(video). These talks do not really qualify as architecture overview replacing this old deck

[donhui]

@oleg-nenashev The slide and video you mentioned are very useful for one who want to know more about remoting. It is really great!

[jglick]

The middle section is indeed specific to TCP transport. OTOH the WebSocket transport is conceptually much simpler (there is not a lot to say about it), and the beginning and final sections are independent of transport and remain valid descriptions.

[oleg-nenashev]

Thanks for the patch @donhui ! Any contributions are welcome and much appreciated. I will try to spend some time and to add materials I know about