Use header to determine scheme
Use header to determine scheme

As requests can pass through intermediates likes load-balancers we might
not have the information anymore if the request was encrypted or not.
In order to construct correct URLs for pagination and location we need
to preserve this information by checking the content of the
`X-Forwarded-Proto` header.

tapglue/snaas,tapglue/snaas,tapglue/snaas