Fix error message on missing requested signature

We don't really distinguish between missing or non-authorizing
signature. And that's fine. See #170

NEWS.md

@@ -4,7 +4,7 @@
 Enhancements:
 
  - Set statsd prefix for all endpoints 
- - Raise 403 forbidden on attempt to access map tiles waiving
+ - Respond with a permission denied on attempt to access map tiles waiving
    signature of someone who had not left any (#170)
 
 1.8.4 -- 2014-03-03

lib/cartodb/server_options.js

@@ -654,11 +654,7 @@ module.exports = function(){
                   }
 
                   // if signer name was given, return no authorization
-                  err = new Error("No authorization left by '"
-                                  + req.params.signer + "' on map '"
-                                  + req.params.token + "'");
-                  err.http_status = 403;
-                  callback(err);
+                  callback(null, false); 
                   return;
                 }
 

test/acceptance/multilayer.js

@@ -138,10 +138,10 @@ suite('multilayer', function() {
               headers: {host: 'localhost' },
               encoding: 'binary'
           }, {}, function(res) {
-              assert.equal(res.statusCode, 403, res.statusCode + ':' + res.body);
+              assert.equal(res.statusCode, 401, res.statusCode + ':' + res.body);
               var parsed = JSON.parse(res.body);
               var msg = parsed.error; // TODO: should it be "errors" ?
-              assert.ok(msg.match(/no authorization left/i), msg);
+              assert.ok(msg.match(/permission denied/i), msg);
               next(err);
           });
         },