Reproduction steps:
1. Create a multi-job project in the Jenkins root
2. Create a folder in the Jenkins root (e.g. "folder")
3. Create a job in the folder (e.g. "foo")
4. Set it as one of the phases of the multi-job build and save
5. Create a view (e.g. "MyView") in the root, include the multi-job project there
6. Go to the view, open the multijob project there
7. If you click on the reference to the job in the folder, the URL points to a non-existent page

Example of the broken link: http://localhost:8080/jenkins/view/MyView/job/foo/

• Folder link is lost, because shortUrl does not retain it
• If we try this case without a View, everything works well => probably there is a bug in Jenkins core

I propose too replace the implementation to Job's absolute url in order to always produce a valid link. The current approach won't work in general, because Views may not contain the multijob's items