fix test error

[monkey92t]

fix test error:

The critical value of time may appear to cause test errors, link: https://github.com/redis/redis/blob/5b48d900498c85bbf4772c1d466c214439888115/src/object.c#L1265-L1272

• Failure [0.068 seconds]
Commands
/redis/commands_test.go:17
  keys
  /redis/commands_test.go:304
    should Object [It]
    /redis/commands_test.go:462

    Expected
        <time.Duration>: 1000000000
    to equal
        <time.Duration>: 0

    /redis/commands_test.go:473

---

In addition, I tracked down more test errors: CLUSTERDOWN The cluster is down.
but I can't determine the cause for the time being. It may be redis-server instability or go-redis cluster problems. I will keep track of them.

I still can't reproduce #1657, maybe it's a problem with my test environment?
The go developers said that it might be a problem with pool: sync.pool{}, but they can’t confirm it.
We can wait for the go developers’ investigation results, link: golang/go#44672

[vmihailenco]

Thanks 👍

[vmihailenco]

We can wait for the go developers’ investigation results, link: golang/go#44672

Let's keep discussion in #1657. Hopefully we will accumulate enough data to get this fixed.