ctx.request.origin is different  to request.headers.origin
I was struggling with CORS setting, and I've found that the ctx.reuqest.origin value is different to ctx.request.headers.origin value.

Client side - https://www.example.com
API server - https://api.example.com

In this situation, ctx.request.headers.origin was https://www.example.com, but ctx.request.origin was https://api.example.com.

Is it intended? I don't know maybe I'm misunderstanding something, but first time I saw the ctx.request.origin, I though it will indicate where the fetch originates from by its naming.
