ikev1: Only delete redundant CHILD_SAs if configured

If we find a redundant CHILD_SA (the peer probably rekeyed the SA before
us) we might not want to delete the old SA because the peer might still
use it (same applies to old CHILD_SAs after rekeyings).  So only delete
them if configured to do so.

Fixes #2358.

src/libcharon/sa/ikev1/task_manager_v1.c

@@ -1805,8 +1805,12 @@ METHOD(task_manager_t, queue_child_rekey, void,
 		if (is_redundant(this, child_sa))
 		{
 			child_sa->set_state(child_sa, CHILD_REKEYED);
-			queue_task(this, (task_t*)quick_delete_create(this->ike_sa,
+			if (lib->settings->get_bool(lib->settings, "%s.delete_rekeyed",
+										FALSE, lib->ns))
+			{
+				queue_task(this, (task_t*)quick_delete_create(this->ike_sa,
 												protocol, spi, FALSE, FALSE));
+			}
 		}
 		else
 		{