added workaround for epsg 6697

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

@@ -388,6 +388,9 @@ public class CityGmlParser {
 				return null;
 			}
 		}
+		if (srsName.equals("http://www.opengis.net/def/crs/EPSG/0/6697")) {
+			return CRS_FACTORY.createFromParameters("EPSG:6697", "+proj=longlat +ellps=GRS80 +no_defs ");
+		}
 		return null;
 	}