This makes two changes to the HAProxy documentation:
1) Replaces the `reqadd` statements with `http-request set-header` statements, including a dynamic `X-Forwarded-Host`. Rationale is that this is cleaner (no manual adding of domain), and extensible to a multi-domain environment. Note that I have NOT tested the `:[port]` trick on this form of the command since I run on port 443.
2) Moves the `redirect scheme` from the backend to the frontend. I disagree with the logic of the commit (002275468a) that moved this to the backend - in a multi-backend environment, putting it in the frontend is cleaner, and in this simple config it makes no functional difference.
This setting is by default in the configuration files in the "default" section, so we don't need to add it here ! ( If someone uses the tcp mode or else he sure knows how haproxy works ! )