remove /var/log/rally in rally dockerfile
remove /var/log/rally in rally dockerfile

Change-Id: Ib0855625b25098311546ecb9bca98c7379584e21

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