Zabbix API doesn't support OPTION request when API client does CORS

When accessing the api throug javascript form another domain the client does an HTTP OPTION request to determine the CORS rules on the server the API is running on.
SInce this request has the wrong content type a 412 error code is returned by the API.

Please allow OPTION requests with all content types so the zabbix API can be access through javascript hosted on another domain than the API.