Fix: Fix database failure due to special chars

CityDoctorParent/CityDoctorModel/src/main/java/de/hft/stuttgart/citydoctor2/database/DatabaseHandler.java

@@ -47,7 +47,7 @@ public class DatabaseHandler {
     }
 
     public DatabaseHandler(String fileName){
-        this.fileName = fileName;
+        this.fileName = "\"" + fileName + "\"";
         setupFeaturesTable();
     }