How to reproduce?

1. Create a simple pipeline:

```
properties([
  parameters([
    string(name: 'test', defaultValue: 'test', description: 'test')
  ]),
])

build(job: "alk-test")
```

2. Set a multiline string parameters for the job (e.g alk-test).

3. Run the pipeline -> when looking at the parameters, the multi-line string (default) is now one line.

I am not able to rebuild the job after that.