proxy
(optional) refer to _proxy for detail
If "use" is set to true, "url" and "port" must be set. "userid" and "password" must be set together. It is recommended to set proxy as this three patterns:
(use = false)
(use = true, url = {url}, port = {port})
(use = true, url = {url}, port = {port}, userid = {userid}, password = {password})