Frontend section in HAProxy config file have been splitted in two.

One for  http and for https.

I have also added a **X-Forwarded-Proto** header to the request for identifying the originating protocol of the  request to the  backend.

 It might make sense to make the second change customizable by doing something similar to the already existing backend configuration. By, for example, adding a **frontend_options** to the `INTERLOCK_DATA` JSON and use it to configure HAProxy. 

Instead of duplicating this whole block would it be easier to add the if in the frontend?  For example:

```
{{ if .Config.SSLCert }}
req X-Forwarded-Proto:\ https
{{ else }}
req X-Forwarded-Proto:\ http
{{ end }}
```