使用独立线程保存设置 (#3929)

HMCL/src/main/java/org/jackhuang/hmcl/Launcher.java

@@ -27,6 +27,7 @@ import javafx.scene.input.DataFormat;
 import javafx.stage.Stage;
 import org.jackhuang.hmcl.setting.ConfigHolder;
 import org.jackhuang.hmcl.setting.SambaException;
+import org.jackhuang.hmcl.util.FileSaver;
 import org.jackhuang.hmcl.task.AsyncTaskExecutor;
 import org.jackhuang.hmcl.task.Schedulers;
 import org.jackhuang.hmcl.ui.Controllers;
@@ -214,6 +215,7 @@ public final class Launcher extends Application {
     @Override
     public void stop() throws Exception {
         Controllers.onApplicationStop();
+        FileSaver.shutdown();
         LOG.shutdown();
     }