Use JJBConfig() class
Use JJBConfig() class

Prevent temptation for other contributors to somehow depend on an
implementation detail of the builder.Jenkins.jobs property.

Change-Id: If6477db1f5bfe8f31d099f21614e894834faf009

dataxu/jenkins-job-builder,wsoula/jenkins-job-builder,twc-openstack/jenkins-job-builder,rsig/jenkins-job-builder,OSSystems/jenkins-job-builder,dataxu/jenkins-job-builder,puppetlabs/jenkins-job-builder,wsoula/jenkins-job-builder,wsoula/jenkins-job-builder,OSSystems/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,tamac-io/jenkins-job-builder,phinexus/jenkins-job-builder,tamac-io/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,rsig/jenkins-job-builder,onshape/jenkins-job-builder,tamac-io/jenkins-job-builder,onshape/jenkins-job-builder,gforcada/jenkins-job-builder,puppetlabs/jenkins-job-builder,dataxu/jenkins-job-builder,rsig/jenkins-job-builder,onshape/jenkins-job-builder,twc-openstack/jenkins-job-builder,wsoula/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,phinexus/jenkins-job-builder,gforcada/jenkins-job-builder,gforcada/jenkins-job-builder,phinexus/jenkins-job-builder,twc-openstack/jenkins-job-builder,tamac-io/jenkins-job-builder,OSSystems/jenkins-job-builder,OSSystems/jenkins-job-builder,rsig/jenkins-job-builder,twc-openstack/jenkins-job-builder,gforcada/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,phinexus/jenkins-job-builder,puppetlabs/jenkins-job-builder,dataxu/jenkins-job-builder,phinexus/jenkins-job-builder,wikimedia/integration-jenkins-job-builder,puppetlabs/jenkins-job-builder,onshape/jenkins-job-builder,gforcada/jenkins-job-builder