SwingTaskMonitorComponent: fix field access bug

Gotta use the class field, not the local variable. Otherwise the class's
enableCancelConfirmation and disableCancelConfirmation have no effect.

Author: ctrueden

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

@@ -202,7 +202,7 @@ public void mouseClicked(java.awt.event.MouseEvent evt) {
                 if (row >= 0 && col == 1) {
                     Task selectedTask = taskTableModel.getTask(row);
                     if (selectedTask!=null) {
-                        if (confirmBeforeCancel) {
+                        if (SwingTaskMonitorComponent.this.confirmBeforeCancel) {
                             int userconfirmation = JOptionPane.showConfirmDialog(null, "Do you really want to cancel this task ?", "Canceling " + selectedTask.getName(), JOptionPane.YES_NO_OPTION);
                             if (userconfirmation == JOptionPane.YES_OPTION) {
                                 selectedTask.cancel("User cancellation (table task)");