Remove unused chunks method
Remove unused chunks method

refers to https://github.com/GIScience/orstools-qgis-plugin/commit/7dd46b4e548b0b6a18e3126900803ca22e1f2039
refers to https://github.com/GIScience/orstools-qgis-plugin/issues/133

nilsnolde/ORStools,nilsnolde/ORStools