MEDIUM: http: add "redirect scheme" to ease HTTP to HTTPS redirection

For instance :

   redirect scheme https if !{ is_ssl }

Backport-suggested-by: Russell Geldmacher <russell.geldmacher@gmail.com>
(cherry picked from commit 2e1dca8f5238155cbc52d37316fe858c4f61cf34)
BUILD: proto_tcp: remove a harmless warning

The "pol" variable was not used and gcc 4.7 emits a warning on it.