setup.backend.{name} in toml always create backend with overide_host set as the address

[noguxun]

In toml, get below setup, notice that there is no setting field override_host .

[setup]
  [setup.backends]
    [setup.backends.example]
      address = "example.org"
      description = "example"
      port = 443

After running fastly compute publish We get a service with a backend that has "override host" set to example.org

Currently, there is no way to set up a backend with an empty "override host"