Newer httpclient 5 API breaks tests of the docker plugin

[MarkEWaite]

Jenkins and plugins versions report

Environment summary

• Fails tests: Ubuntu 22.04 virtual machine agent on ci.jenkins.io with Docker installed and authorized, but with no Docker daemon available on port 2375
• Fails tests: Debian testing with Docker installed and authorized for my user account, but with no Docker daemon available on port 2375
• Passes tests: Ubuntu 22.04 with Docker installed and authorized for my user account and with a Docker daemon available on port 2375

What Operating System are you using (both controller, and any agents involved in the problem)?

Ubuntu 22.04 and Debian without Docker listening on port 2375 fails tests when testing with apache-httpcomponents-client-5-api 5.4-118.v199115451c4d . The same tests pass if tested with apache-httpcomponents-client-5-api 5.3.1-110.v77252fb_d4da_5

Ubuntu 22.04 and Debian with Docker listening on port 2375 passes tests with both versions of apache-httpcomponents-client-5-api

Reproduction steps

1. Run tests on ci.jenkins.io or on a local computer that does not have a Docker listener on port 2375, confirm tests fail unless the apache-httpcomponents-client-5-api library used in the test is forced to 5.3.1-110.v77252fb_d4da_5

Expected Results

Tests should pass with both the older and the newer version of the apache-httpcomponents-client-5-api library

Actual Results

Test fail unexpectedly unless a Docker listener is available on port 2375

Anything else?

Failure seems to be specific to the tests. Assumed that there is some difference in exception handling between the two versions of the apache-httpcomponents-client-5-api library.

Are you interested in contributing a fix?

Yes, though not sure when time will allow it. A temporary workaround has been applied in:

• #1102