Move nova dependency from haproxy to openstack-ha and fix error

Currently, haproxy has a dependency on nova cookbook but I believe this should be in openstack-ha instead.  Also, default recipe has a reference to roles[0] which should be role.  Looks like that instance was omitted when other roles[0] references were updated in https://github.com/rcbops-cookbooks/openstack-ha/pull/9/files.