added UTF-8 as output charset for writing CityGML files when streaming files

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/parser/CityGmlParser.java

@@ -483,7 +483,7 @@ public class CityGmlParser {
 			return null;
 		}
 		CityGMLOutputFactory factory = builder.createCityGMLOutputFactory();
-		CityModelWriter writer = factory.createCityModelWriter(new File(outputFile));
+		CityModelWriter writer = factory.createCityModelWriter(new File(outputFile), "UTF-8");
 		writer.setPrefix("qual", QualityADEModule.NAMESPACE_URI);
 		writer.setSchemaLocation(QualityADEModule.NAMESPACE_URI,
 				"https://transfer.hft-stuttgart.de/pages/qualityade/0.1/qualityAde.xsd");