Update slave_utilization use of convert_mapping_to_xml()
Update slave_utilization use of convert_mapping_to_xml()

Change-Id: Ifa489ad11f5825b254dd8602cdbd1ff0014736a4

gforcada/jenkins-job-builder,rsig/jenkins-job-builder,phinexus/jenkins-job-builder,rsig/jenkins-job-builder,puppetlabs/jenkins-job-builder,phinexus/jenkins-job-builder,wsoula/jenkins-job-builder,rsig/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,phinexus/jenkins-job-builder,phinexus/jenkins-job-builder,puppetlabs/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,wsoula/jenkins-job-builder,gforcada/jenkins-job-builder,gforcada/jenkins-job-builder,puppetlabs/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,wsoula/jenkins-job-builder,OSSystems/jenkins-job-builder,rsig/jenkins-job-builder,OSSystems/jenkins-job-builder,OSSystems/jenkins-job-builder,phinexus/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,wikimedia/integration-jenkins-job-builder,puppetlabs/jenkins-job-builder,gforcada/jenkins-job-builder,OSSystems/jenkins-job-builder,gforcada/jenkins-job-builder,wsoula/jenkins-job-builder