Update ironic.conf.sample
Update ironic.conf.sample

Change-Id: I0f82d94ff234cc3b78f0cbcac913dff0edca30c0

NaohiroTamura/ironic,openstack/ironic,NaohiroTamura/ironic,bacaldwell/ironic,devananda/ironic,SauloAislan/ironic,SauloAislan/ironic,bacaldwell/ironic,openstack/ironic,pshchelo/ironic,pshchelo/ironic