Fixed parser for govdata.de

govdata.de uses for format-description of csv-files `csv` and not `CSV`, which is usually the default value. By changing the capital letters to lower case letters, the parser works again.
Example dataset: https://www.govdata.de/suchen/-/details/oberbuergermeisterwahl_2012-hro-hro (unfortunately, the lat/lon are in the properties-array and not in the geometry one)