Remove project custom properties with TestRunner

Hello everybody,

I'm looking for a solution to remove custom properties from my project. 

Indeed, during an execution with the TestRunner, I save data in project custom properties and I would like delete them with a script.

This bellow script work fine when I play it with the Test Case execution, but not with the Test Runner Execution : 

 runner.project.properties.each {
if (testRunner.project.properties[it.key].name == 'XRAY-ID'){
log.info('On ne fait rien')
}
else {
if (testRunner.project.properties[it.key].name.contains('P_') == true){
testRunner.project.removeProperty(testRunner.project.properties[it.key].name)
}
}
}

This script is positionned in a Script Test Step.

Do you have an idea ?

Thank you in advance for your help,

Anthony