Fix designate dockerfile
Fix designate dockerfile

change kolla_extend_start to kolla_designate_extend_start

TrivialFix

Change-Id: I34a355aa24e2ff1ff483fa596e190922159a4d0b

GalenMa/kolla,stackforge/kolla,intel-onp/kolla,GalenMa/kolla,mrangana/kolla,coolsvap/kolla,rahulunair/kolla,openstack/kolla,dardelean/kolla-ansible,nihilifer/kolla,coolsvap/kolla,openstack/kolla,intel-onp/kolla,rahulunair/kolla,coolsvap/kolla,mrangana/kolla,stackforge/kolla,stackforge/kolla,dardelean/kolla-ansible,nihilifer/kolla,dardelean/kolla-ansible