False is also a value

[avdata99]

In a field with boolean values like this

- field_name: some_bool
  label: Some Bool
  required: false
  preset: select
  choices:
    - value: false
      label: "No"
    - value: true
      label: "Yes"
  validators: scheming_required boolean_validator
  output_validators: boolean_validator

and if the false value is selected, we didn't display anything in the select

This PR fixes those cases