Update luigi.is-cool.dev.json

Removing NS since it is no longer supported.

domains/luigi.is-cool.dev.json

@@ -9,8 +9,7 @@
         "email": "virtual.employee@gmail.com"
     },
     "record": {
-        "A": ["5.161.122.143"],
-        "NS": ["hydrogen.ns.hetzner.com.","helium.ns.hetzner.de.","oxygen.ns.hetzner.com."]
+        "A": ["5.161.122.143"]
     },
     "proxied": false
 }