fix: 禁止取消未生效 (#5600)

HMCL/src/main/java/org/jackhuang/hmcl/ui/construct/TaskExecutorDialogPane.java

@@ -31,7 +31,6 @@ import org.jackhuang.hmcl.util.TaskCancellationAction;
 import org.jackhuang.hmcl.util.i18n.I18n;
 import org.jetbrains.annotations.NotNull;
 
-import java.util.Optional;
 import java.util.function.Consumer;
 
 import static org.jackhuang.hmcl.ui.FXUtils.onEscPressed;
@@ -83,8 +82,9 @@ public class TaskExecutorDialogPane extends BorderPane {
         setCancel(cancel);
 
         btnCancel.setOnAction(e -> {
-            Optional.ofNullable(executor).ifPresent(TaskExecutor::cancel);
             if (onCancel.getCancellationAction() != null) {
+                if (executor != null)
+                    executor.cancel();
                 onCancel.getCancellationAction().accept(this);
             }
         });