修改警报阈值

修改指定的警报阈值的任何属性。

请求示例：

PUT /api/alert/v1/thresholds/1b15d405-75c4-4c0c-e0f6-8a108165b874
    HTTP/1.1
Authorization: Basic abcd123MWE=
Host: zfssa.example.com:215

{"days":"weekdays"}

响应示例：

HTTP/1.1 202 Accepted
X-Zfssa-Appliance-Api: 1.0
Content-Type: application/json
Content-Length: 326

{
    "threshold": {
        "days": "weekdays",
        ...
    }
}