Add REQUEST_SCHEME to CGI vars passed to php-fpm

roles/webserver/templates/fpm/nginx/fastcgi_pass_fpm.j2

@@ -20,6 +20,7 @@ fastcgi_param   REQUEST_URI         $request_uri;
 fastcgi_param   DOCUMENT_URI        $document_uri;
 fastcgi_param   DOCUMENT_ROOT       $document_root;
 fastcgi_param   SERVER_PROTOCOL     $server_protocol;
+fastcgi_param   REQUEST_SCHEME      $scheme;
 fastcgi_param   HTTPS               $https if_not_empty;
 
 fastcgi_param   GATEWAY_INTERFACE   CGI/1.1;