Revert "ikev2: Insert MOBIKE tasks at the front of the queue"

This reverts commit 3293d14628.

The position of tasks in the queue does not actually determine the order
in which they are activated.  Instead this is determined by the
statements in task_manager_v2_t.initiate().

src/libcharon/sa/ikev2/task_manager_v2.c

@@ -1282,8 +1282,6 @@ METHOD(task_manager_t, process_message, status_t,
 METHOD(task_manager_t, queue_task, void,
 	private_task_manager_t *this, task_t *task)
 {
-	int pos = ARRAY_TAIL;
-
 	if (task->get_type(task) == TASK_IKE_MOBIKE)
 	{	/*  there is no need to queue more than one mobike task */
 		enumerator_t *enumerator;
@@ -1300,12 +1298,9 @@ METHOD(task_manager_t, queue_task, void,
 			}
 		}
 		enumerator->destroy(enumerator);
-		/* insert MOBIKE tasks first as we currently might not have a usable
-		 * path to initiate any other tasks */
-		pos = ARRAY_HEAD;
 	}
 	DBG2(DBG_IKE, "queueing %N task", task_type_names, task->get_type(task));
-	array_insert(this->queued_tasks, pos, task);
+	array_insert(this->queued_tasks, ARRAY_TAIL, task);
 }
 
 /**