[FIX] unfuck set usage

set("web") -> set(['b', 'e', 'w']), which won't do anything.

Use set.discard which removes the value if present or noops if not.

bzr revid: xmo@openerp.com-20130723155729-80y1psxd1h0o82s6

addons/web/http.py

@@ -998,8 +998,8 @@ class Root(object):
                                         url = url[: -1]
                                 routing_map.add(routing.Rule(url, endpoint=function))
 
-        modules_set = set(controllers_per_module.keys())
-        modules_set -= set("web")
+        modules_set = set(controllers_per_module)
+        modules_set.discard('web')
         # building all none methods
         gen(["web"] + sorted(modules_set), True)
         if not db: