jjb: fix jenkins-jobs-wrapper detection of jenkins-job command
jjb: fix jenkins-jobs-wrapper detection of jenkins-job command

* the output was lost, so it was always empty

Change-Id: I3dfdf5c3f64445a9f940f0e13ed0d0bd09fc02f1

sipwise/kamailio-deb-jenkins,sipwise/kamailio-deb-jenkins