UX: CsvCruncher 2.10.1 fails with just `null` on missing `-out`

The missing `-out`  could just treated as `-out -`  (STDOUT).

```
$ crunch -in GroupMembers-onlyGroups.csv -sql 'SELECT *' 
...    
null
  If you believe this is a bug, feel free to report it at https://github.com/OndraZizka/csv-cruncher/issues
  but please check the open tickets first.
```
