Wrong result when using a filter expression on a non-existing child array

RedisJSON 2.6.6

```
redis> JSON.SET x $ '{"a":[1,2,3]}'
OK
redis> JSON.GET x '$.a[0][?(@==1)]'
"[1]"
```

Expected

```
redis> JSON.GET x '$.a[0][?(@==1)]'
"[]"
```

Another example:

```
redis> JSON.GET x '$.a[0][?(@==@)][?1][?2][?3]'
"[1]"
```
