fix(client): if the websocket fails to connect, wait on the socket ho…

…st, not the ping host

The problem with checking the ping host is that the ping host can
pass, even if the socket host fails, leading to infinite reloads.

Infinite reloads are a bad way to deal with this failure.
This makes the failure less bad.

For examples, see:
#6814
#3093

packages/vite/src/client/client.ts

@@ -214,7 +214,9 @@ async function waitForSuccessfulPing(ms = 1000) {
   // eslint-disable-next-line no-constant-condition
   while (true) {
     try {
-      await fetch(`${base}__vite_ping`)
+      // A fetch on a websocket URL will return a successful promise with status 400,
+      // but will reject a networking error.
+      await fetch(`${location.protocol}//${socketHost}`)
       break
     } catch (e) {
       await new Promise((resolve) => setTimeout(resolve, ms))