revert change in devp2p

packages/devp2p/examples/simple.ts

@@ -43,7 +43,5 @@ for (const bootnode of BOOTNODES) {
 }
 
 setTimeout(() => {
-  // After the timeout, destroy dpt
-  dpt.destroy() // NOTE: this does not seem to stop listening to peers, how to quit/exit?
-  // (client also calls `dpt.destroy()` in `rlpxserver` on `stop()`)
+  process.exit()
 }, TIMEOUT)