Make task managers flush_queue() method public

src/libcharon/sa/task_manager.h

@@ -253,6 +253,13 @@ struct task_manager_t {
 	enumerator_t* (*create_task_enumerator)(task_manager_t *this,
 											task_queue_t queue);
 
+	/**
+	 * Flush a queue, cancelling all tasks.
+	 *
+	 * @param queue			queue to flush
+	 */
+	void (*flush_queue)(task_manager_t *this, task_queue_t queue);
+
 	/**
 	 * Destroy the task_manager_t.
 	 */