fix: crash of closeEvent in racewindow and settingsmenu + code cleanup

result.cpp

@@ -22,7 +22,7 @@ using std::endl;
 using std::string;
 using std::vector;
 
-Result::Result(DataBase * db, int rennid, QWidget * parent)
+Result::Result(std::shared_ptr<DataBase> db, int rennid, QWidget * parent)
     : QWidget(parent), ui(new Ui::Result) {
     ui->setupUi(this);
     this->db = db;