Enum query parameters are always added to request

[woefe]

Query parameters of enum types are always added to the request, even if they are optional.

To reproduce:

1. Load https://gist.githubusercontent.com/woefe/7204b386a69ad31776f3d733229a346f/raw/5dc44e50fe09b747a19888a1f573c1996699eaee/schema.yml into OpenAPI Explorer
2. Go to "Get users" operation
3. There's no way to deselect the status query parameter

Is it possible to add a default "not set" option to the select dropdown of optional enum query parameters?

[wparad]

Fixed in the latest version. Thanks for reporting this.

[woefe]

I noticed that the "clear" button does not clear the select input. Created #283 as follow up