Update javascript.react-router.mdx

Author: chargome

platform-includes/getting-started-config/javascript.react-router.mdx

@@ -84,7 +84,7 @@ Create an `instrument.server.mjs` file in the root of your app:
 import * as Sentry from "@sentry/node";
 
 Sentry.init({
-  dsn: "https://c122e7637b24dc299bbef9d4e80c8325@o4507458071298048.ingest.de.sentry.io/4508415844876368",
+  dsn: "___PUBLIC_DSN___",
   tracesSampleRate: 1.0, // Capture 100% of the transactions
 });
 ```