Fix incorrect redirection to HTTP whereas the initial request is over HTTPS

Nuxeo is configured behing a Apache that rewrites requests to use HTTPS.
With the following scenario, the user is redirected to a HTTP URL:

• navigate to https://server/nuxeo
• log in
• the system displays the requested page still under HTTPS
• change the URL in the address bar to navigate to https://server/nuxeo
• the system displays the requested page, but now under HTTP