Calling close() on a ViteDevServer instance that was never started throws

[ggoodman]

Describe the bug

When using the programmatic SSR API of a ViteDevServer instance in another server, attempting to dispose of the instance via the close method will throw when the http server has not been started.

Reproduction

const Vite = require('vite');

Vite.createServer().then((vite) => {
  vite.close();
});

Will throw an uncaught exception:

Error [ERR_SERVER_NOT_RUNNING]: Server is not running.
    at Server.close (net.js:1606:12)
    at Object.onceWrapper (events.js:421:28)
    at Server.emit (events.js:315:20)
    at emitCloseNT (net.js:1659:8)
    at processTicksAndRejections (internal/process/task_queues.js:79:21)

via

vite/packages/vite/src/node/server/index.ts

Lines 315 to 320 in b2110af

	await Promise.all([
	watcher.close(),
	ws.close(),
	container.close(),
	closeHttpServer()
	])

Perhaps an easy fix would be to add an additional condition on || !server.listening here:

vite/packages/vite/src/node/server/index.ts

Line 583 in b2110af

if (!server) {

System Info

• vite version: 2.0.0-beta.62
• Operating System: MacOS 11.2
• Node version: v14.15.4
• Package manager (npm/yarn/pnpm) and version: 6.14.10

Logs (Optional if provided reproduction)

1. Run vite or vite build with the --debug flag. N/A
2. Provide the error log here. See above

[CHOYSEN]

Perhaps an easy fix would be to add an additional condition on || !server.listening here:

vite/packages/vite/src/node/server/index.ts

Line 583 in b2110af

if (!server) {

PR Welcome!