update discord link (#5940)

# Motivation

Original #5931

# Changes

- Updated the Discord link in the README.

# Tests

Not necessary

# Todos

- [ ] Add entry to changelog (if necessary).
Not necessary

README.md

@@ -10,7 +10,7 @@
 
 [![GitHub Workflow Status (with event)](https://img.shields.io/github/actions/workflow/status/dfinity/nns-dapp/build.yml?logo=github&label=Build%20and%20test)](https://github.com/dfinity/nns-dapp/actions/workflows/build.yml)
 <a href="https://github.com/dfinity/nns-dapp/releases"><img src="https://img.shields.io/github/downloads/dfinity/nns-dapp/total?label=downloads&logo=github" alt="GitHub all releases"></a>
-[![Chat on Discord](https://img.shields.io/badge/chat-Discord-lightgrey?logo=Discord&style=flat-square)](https://discord.gg/E9FxceAg2j)
+[![Chat on Discord](https://img.shields.io/badge/chat-Discord-lightgrey?logo=Discord&style=flat-square)](https://discord.internetcomputer.org)
 
 </div>