How can I disable "scheduler_hints" in Nova:Server creation if the "enable_anti-affinity" is set to False?

heat_template_version: 2017-09-01
parameters:
    enable_anti-affinity:
    type: string
    default: False
conditions:
  cnd_enable_anti-affinity: { equals: [{get_param: enable_anti-affinity}, "False"]}
resources:
    stack-server-group:
      type: OS::Nova::ServerGroup
      condition: cnd_enable_anti-affinity
      properties:
        name: server-group1
        policies: [ 'soft-anti-affinity' ]
    node01_server:
     type: OS::Nova::Server
     properties:
       name: server01
       image: some_image
       flavor: some_flavor
       scheduler_hints:
         group: { get_resource: stack-server-group }