DataSource location default values are not properly used in Read()

[kklimonda-cl]

The following data source doesn't work, as default value for panorama_device is not properly propagated form terraform to Go SDK. However, this part of code is shared between resources and datasources and resources work fine.
Once panorama_device is uncommented, resources are read from the server properly.

data "panos_addresses" "example" {
  location = {
    device_group = {
      name            = "DG"
      #panorama_device = "localhost.localdomain"
    }
  }

  addresses = {
    "foo" = {

    }
    "bar" = {

    }
  }
}