Plugin delete Advanced Configuration in Execute shell slicer

[FrancoCapraro]

Jenkins and plugins versions report

Hello, we use this plugin a lot in Orange IaaS to change the Freestyles Shells easily. The issue start when we use "Execute shell slicer" option.
First of all we use a Shell Terminal (in Build Task) with Advanced option enabled "Mark as unstable with a return value", to return a Unstable when return =100.
The code associate in XML is :

<unstableReturn>100</unstableReturn>

If we modify some shell using "Execute shell slicer" option, this modification DELETE the Advanced code.
I think that it can be interesting to modify the Advanced part from this plugin or at least dont delete it.

What Operating System are you using (both controller, and any agents involved in the problem)?

Linux

Reproduction steps

The way to test this:

1. Create a Freestyle Job (i.e: "MY_JOB")
2. Add a Shell Task in Build Task
3. Select the Advanced Option and write "100"
4. Print the XML (cat $ADDRESS/config.xml)
5. Modify "MY_JOB" with ConfigurationSlicing Plugin
6. Print the XML again (cat $ADDRESS/config.xml)

Expected Results

<unstableReturn>100</unstableReturn> Not Deleted

Actual Results

<unstableReturn>100</unstableReturn> Deleted

Anything else?

No response