fix cancel not called when no user confirmation is required

Author: NicoKiaru

src/main/java/org/scijava/ui/swing/task/SwingTaskMonitorComponent.java

@@ -238,6 +238,8 @@ public void mouseClicked(java.awt.event.MouseEvent evt) {
 							if (userconfirmation == JOptionPane.YES_OPTION) {
 								selectedTask.cancel("User cancellation (table task)");
 							}
+						} else {
+							selectedTask.cancel("User cancellation (table task)");
 						}
 					}
 				}