With Monitoring plugin version 2.9.0, clicking Monitoring under Manage Jenkins generates an incorrect URL when Jenkins is deployed with a context path.

The generated URL contains an additional "." before the /monitoring path.

Steps to reproduce:
Deploy Jenkins 2.580.1 with a context path, for example /release_testing_jdk25.
Install Monitoring plugin version 2.9.0.
Open Manage Jenkins.
Click Monitoring.
Observe the URL in the browser.

Actual result

The browser is redirected to:

https://<domainname.com>/release_testing_jdk25../monitoring

The URL contains an additional "." before /monitoring.

Expected result

The browser should be redirected to:
https://<domainname.com>/release_testing_jdk25/monitoring

Comparison / isolation test

The issue was reproduced with Monitoring plugin 2.9.0 on Jenkins 2.580.1.

The same Jenkins 2.580.1 instance was then tested after downgrading the Monitoring plugin to version 2.8.0.

Monitoring 2.9.0 + Jenkins 2.580.1: Issue occurs
Monitoring 2.8.0 + Jenkins 2.580.1: Issue does not occur

This indicates that the issue is likely a regression introduced in Monitoring plugin 2.9.0 rather than a Jenkins 2.580.1 issue.