This issue has already been fixed in the jenkins-ssh-slave docker image here https://github.com/Ouranosinc/jenkins-ssh-slave/pull/2 but still not deployed because for an unknown reason the new rebuild of jenkins-ssh-slave docker image do not work with the jenkins-master (master is unable to connect to the slave over ssh).
This issue has already been fixed in the jenkins-ssh-slave docker image here https://github.com/Ouranosinc/jenkins-ssh-slave/pull/2 but still not deployed because for an unknown reason the new rebuild of jenkins-ssh-slave docker image do not work with the jenkins-master (master is unable to connect to the slave over ssh).