Job configuration with environment variables are changed during build

If environment variables is used in any of the fields that supports it, thoes fields will change with the expanded value when running a build.

E.g. If the job is configured with:

Path to exec files:
targets/${TARGET}/*.exec

Running a build with TARGET set to "dummy", the configuration afterwards will be:

Path to exec files:
targets/dummy/*.exec

This is fixed in pull request:
https://github.com/jenkinsci/jacoco-plugin/pull/94