fix(server-render): handling error in async setup

[edison1105]

close #2736
I only dealt with the exception information in errorCaptured.
Because there is already a warning message in async setup and prefetch.
This is inconsistent with vue2.
IMO, there is no need to adjust.

  if (hasAsyncSetup || prefetch) {
    let p = hasAsyncSetup
      ? (res as Promise<void>).catch(err => {
          warn(`[@vue/server-renderer]: Uncaught error in async setup:\n`, err)
        })
      : Promise.resolve()
    if (prefetch) {
      p = p.then(() => prefetch.call(instance.proxy)).catch(err => {
        warn(`[@vue/server-renderer]: Uncaught error in serverPrefetch:\n`, err)
      })
    }
    return p.then(() => renderComponentSubTree(instance))
  }