Extract originIp and OriginHost. (#57)
Extract originIp and OriginHost. (#57)

* Extract originIp and OriginHost.

* Make header x-forwarded-host const.

FirebasePrivate/proxy,gurgenh/proxy,FirebasePrivate/proxy,qiwzhang/proxy,qiwzhang/proxy,gurgenh/proxy,FirebasePrivate/proxy,istio/proxy,gurgenh/proxy,lizan/proxy,lizan/proxy,lizan/proxy,istio/proxy,gurgenh/proxy,istio/proxy,FirebasePrivate/proxy,FirebasePrivate/proxy,gurgenh/proxy,istio/proxy,qiwzhang/proxy,lizan/proxy,qiwzhang/proxy,qiwzhang/proxy