ProxyConfiguration currently doesn't follow standard patterns for encapsulation

Half of its fields are public and on the Jenkins instance it is public as well

JCasC works by standard conventions being followed

Currently this is being worked around in JCasC with a configurator but these are intended to be temporary and removed as soon as upstream code is made compatible

https://github.com/jenkinsci/configuration-as-code-plugin/blob/6671f8d69bdb0e24aa6ac3569e12e38e075944cc/plugin/src/main/java/io/jenkins/plugins/casc/core/ProxyConfigurator.java#L58-L77