Use Nginex as Jenkins reverse proxy instead on Apache

The following issue: JENKINS-47279 indicated there is currently no way to expose the Jenkins CLI over HTTP/HTTPs.

The Jenkins CLI is essential to access parts of the Jenkins internal API that allow detecting internal requirements for hosts, this in turn is essential for having a service running inside a firewalled network that provides specialized hosts to our public Jenkins instance.

The main use case for this is providing RHEL BM host from the Red Hat network to the oVirt Jenkins.