fix typo (nuxt#790)

Arno Schutijzer · atinux · commit c4a588b7e4d4 · 2018-09-30T18:23:51.000+02:00
diff --git a/en/faq/host-port.md b/en/faq/host-port.md
@@ -20,10 +20,9 @@ Or
 }
 ```
 
+## Configure in `nuxt.config.js`:
 
-## Configure in `nuxt.config.json`:
-
-Inside your `nuxt.config.json`:
+Inside your `nuxt.config.js`:
 
 ```js
 module.exports = {
