ProxyFromEnvironment does not work as expected

As per the debugging session in chat the `-proxy` handling does not work as expected under some conditions. This for example works in `httphelpers.go` but not the `ProxyFromEnvironment`:

```go
Proxy: http.ProxyURL(&url.URL{
	Scheme: "http",
	Host:   "127.0.0.1:8081",
}),```
