ckan_pycsw.py cannot run on Python 3.2 or greater

```
File "/usr/lib/ckan/venv/src/ckanext/ckanext-spatial/bin/ckan_pycsw.py", line 27, in setup_db
table_name = pycsw_config.get("repository", "table", "records")
TypeError: get() takes 3 positional arguments but 4 were given
```

> Changed in version 3.2: Arguments raw, vars and fallback are keyword only to protect users from trying to use the third argument as the fallback fallback (especially when using the mapping protocol).
-- https://docs.python.org/3/library/configparser.html#configparser.ConfigParser.get