README: move IRC channel

README.md

@@ -11,7 +11,7 @@
 [Nix](https://nixos.org/nix/) expressions related to the
 [Genode OS framework](https://genode.org).
 
-**IRC:** irc://oftc.net/#genodepkgs
+**IRC:** irc://freenode.net/#nixos-exotic
 
 **Mailing List:** https://lists.sr.ht/~ehmry/genodepkgs