Do not initialize status code to 404 when method is OPTIONS

lib/cartodb/api/middlewares/initialize-status-code.js

@@ -1,6 +1,9 @@
 module.exports = function initializeStatusCode () {
     return function initializeStatusCodeMiddleware (req, res, next) {
-        res.statusCode = 404;
+        if (req.method !== 'OPTIONS') {
+            res.statusCode = 404;
+        }
+
         next();
     };
 };