ikev1: Activate task to delete the IKE_SA in state IKE_REKEYING

It does not have any CHILD_SAs attached at that point.

src/libcharon/sa/ikev1/task_manager_v1.c

@@ -547,6 +547,14 @@ METHOD(task_manager_t, initiate, status_t,
 					break;
 				}
 				break;
+			case IKE_REKEYING:
+				if (activate_task(this, TASK_ISAKMP_DELETE))
+				{
+					exchange = INFORMATIONAL_V1;
+					new_mid = TRUE;
+					break;
+				}
+				break;
 			default:
 				break;
 		}