Is it possible to override the "Jenkins URL" configured in Jenkins?

In our environment the optional "Jenkins URL" has been set - to allow embedding of a user addressable URL in emails etc (as far as I understand).

This gives me a problem when using this library from a different server-based environment, as the Job URL has this configured "Jenkins URL" applied to it. The resulting URL, which is used in `job.build(true)`, isn't addressable from my server.

If the "Jenkins URL" is removed then `job.build(true)` uses the address which my code supplies when creating the JenkinsServer.

Is there a way to stop the Jenkins URL (while it is set for other reasons) being used and always use the supplied address?