Fix for occassional 400 - too many headers
Fix for occassional 400 - too many headers

When request contains `Host:` header (which can happen e.g. when offloading request through internal uwsgi routing), we will end up with two Host headers (another from HTTP_HOST uwsgi var). Which in Golang http server results in an error when using HTTP/1.1.

https://github.com/golang/go/blob/release-branch.go1.8/src/net/http/server.go#L954
23doors/go-uwsgi