docs(security): typo in X-Forwarded-For header

Author: Scrip7

content/security/rate-limiting.md

@@ -39,7 +39,7 @@ There is also the `@Throttle()` decorator which can be used to override the `lim
 
 #### Proxies
 
-If your application runs behind a proxy server, check the specific HTTP adapter options ([express](http://expressjs.com/en/guide/behind-proxies.html) and [fastify](https://www.fastify.io/docs/latest/Server/#trustproxy)) for the `trust proxy` option and enable it. Doing so will allow you to get the original IP address from the `X-Forward-For` header, and you can override the `getTracker()` method to pull the value from the header rather than from `req.ip`. The following example works with both express and fastify:
+If your application runs behind a proxy server, check the specific HTTP adapter options ([express](http://expressjs.com/en/guide/behind-proxies.html) and [fastify](https://www.fastify.io/docs/latest/Server/#trustproxy)) for the `trust proxy` option and enable it. Doing so will allow you to get the original IP address from the `X-Forwarded-For` header, and you can override the `getTracker()` method to pull the value from the header rather than from `req.ip`. The following example works with both express and fastify:
 
 ```ts
 // throttler-behind-proxy.guard.ts