use custom rate limit key generator due to cf changes

addon/serverless.js

@@ -12,7 +12,8 @@ const router = getRouter({ ...addonInterface, manifest: manifest() });
 const limiter = rateLimit({
   windowMs: 60 * 60 * 1000, // 1 hours
   max: 300, // limit each IP to 300 requests per windowMs
-  headers: false
+  headers: false,
+  keyGenerator: (req) => requestIp.getClientIp(req)
 });
 
 router.use(limiter);