[Swift4] enum cases are disappeared

Created by: d-date

Description

All of enum cases are disappeared.

openapi-generator version

4.0.0 (master)

OpenAPI declaration file content or url

Order:
    type: object
    properties:
      id:
        type: integer
        format: int64
      petId:
        type: integer
        format: int64
      quantity:
        type: integer
        format: int32
      shipDate:
        type: string
        format: date-time
      status:
        type: string
        description: Order Status
        enum:
          - placed
          - approved
          - delivered
      complete:
        type: boolean
        default: false
    xml:
      name: Order

Command line used for generation

./bin/swift4-all.sh

Steps to reproduce

Related issues/PRs

Suggest a fix