Trouble with multi-kernel configuration

In Hopper GPU, the multi-stream configuration like ospert_2017_figure_6.json, the code can not run:
```
Block and grid dims must be positive.
Missing/invalid benchmark thread_count in config.
Failed initializing the task host.
```

It seems that your parser will throw error when:
```
      "thread_count": 0,
      "block_count": 0,
      "data_size": 0,
```

