Schema type incorrectly set when omitted and additionalProperties given

[spacether]

Schema type incorrectly set when omitted and additionalProperties given

Swagger-parser version: 2.0.31

Sample spec:

openapi: 3.0.3
info:
  title: openapi 3.0.3 sample spec
  description: sample spec for testing openapi functionality, built from json schema
    tests for draft6
  version: 0.0.1
paths: {}
components:
  schemas:
    PropertyNamedRefThatIsNotAReference:
      properties:
        $ref:
          type: string
    RefInAdditionalproperties:
      additionalProperties:
        $ref: '#/components/schemas/PropertyNamedRefThatIsNotAReference'

For RefInAdditionalproperties, type should be unset but the parser sets it to object