Latest version 2.16.1, when load dataset error occurs. ValueError: BuilderConfig 'allenai--c4' not found. Available: ['default']
### Describe the bug

python script is:
```

from datasets import load_dataset
cache_dir = 'path/to/your/cache/directory'
dataset = load_dataset('allenai/c4','allenai--c4', data_files={'train': 'en/c4-train.00000-of-01024.json.gz'}, split='train',  use_auth_token=False, cache_dir=cache_dir)
```


the script success when datasets version is 2.14.7. 
when using 2.16.1, error occurs
`
ValueError: BuilderConfig 'allenai--c4' not found. Available: ['default']`

### Steps to reproduce the bug

1. pip install datasets==2.16.1
2. run python script:
```

from datasets import load_dataset
cache_dir = 'path/to/your/cache/directory'
dataset = load_dataset('allenai/c4','allenai--c4', data_files={'train': 'en/c4-train.00000-of-01024.json.gz'}, split='train',  use_auth_token=False, cache_dir=cache_dir)
```

### Expected behavior

the dataset should be loaded successful in the latest version. 

### Environment info

datasets 2.16.1