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.