update host.v1 fails if proxy not defined

[qrkourier]

Input validation fails when updating a host.v1 config that does not use the proxy field. I didn't expect it to be required.

{
    "cause": {
        "field": "proxy.type",
        "reason": "proxy.type is invalid: proxy.type: proxy.type must be one of the following: \"http\"",
        "value": ""
    },
    "code": "COULD_NOT_VALIDATE",
    "message": "The supplied request contains an invalid document or no valid accept content were available, see cause",
    "requestId": "JOuLW2j6V"
}