Old-style logging configuration sets defaults but new-style logging does not

# Problem

When using "old-style" logging, i.e., not specifying `version`, `distributed` sets default levels and handlers:
```python3
import dask
import logging

dask.config.set({"distributed.logging": {}})
import distributed
logger = logging.getLogger("distributed")
```

```python3
>>> logger

```
```python3
>>> logger.handlers
[]
```

When using "new-style" logging, `distributed` does not set any defaults or handlers:
```python3
import dask
import logging

dask.config.set({"distributed.logging": {"version": 1}})
import distributed
logger = logging.getLogger("distributed")
```
```python3
>>> logger

```
```python3
>>> logger.handlers
[]
```

# Expected behavior

The two configuration methods should behave the same way.