`TestStatsNoStream` is failing

This test started failing after https://github.com/nginxinc/nginx-plus-go-client/pull/174 but the pipeline wasn't failing on the error

```
test-no-stream-1  | === RUN   TestStatsNoStream
test-no-stream-1  |     client_no_stream_test.go:38: No stream block should result in StreamZoneSync = `nil`
test-no-stream-1  | --- FAIL: TestStatsNoStream (0.01s)
```
