Consumer Source Field Nullability

[scottf]

Making sure nullability matches schema

"stream_consumer_source": {
  "type": "object",
  "description": "Consumer information for durable sourcing",
  "required": ["name", "deliver_subject"],
  "properties": {
    "name": {
      "description": "Consumer name",
      "$ref": "#/definitions/basic_name"
    },
    "deliver_subject": {
      "description": "The subject to deliver messages to",
      "type": "string"
    }
  }
},

[mtmk]

LGTM