[FIX] http_routing: fix request.redirect withtout website installed

In case you have a controller website=True without website installed, the
request.redirect() use url_for which one uses request.website_routing on the
request, without that it has been set by the website dispatcher.

closes odoo/odoo#38191

Signed-off-by: Jérémy Kersten (jke) <jke@openerp.com>

addons/http_routing/models/ir_http.py

@@ -182,7 +182,8 @@ def url_for(url_from, lang_code=None, no_rewrite=False):
     new_url = False
 
     # don't try to match route if we know that no rewrite has been loaded.
-    if not request.env['ir.http']._rewrite_len.get(request.website_routing):
+    routing = getattr(request, 'website_routing', None)  # not modular, but not overridable
+    if not request.env['ir.http']._rewrite_len.get(routing):
         no_rewrite = True
 
     # avoid useless check for 1 char URL '/', '#', ... and absolute URL