fix: Do not replace NAT gateways when additional subnets are added (#1055)

fix: Do not replace nat gateways when new private subnets are added

main.tf

@@ -1052,7 +1052,7 @@ resource "aws_route" "private_ipv6_egress" {
 
 locals {
   nat_gateway_count = var.single_nat_gateway ? 1 : var.one_nat_gateway_per_az ? length(var.azs) : local.max_subnet_length
-  nat_gateway_ips   = var.reuse_nat_ips ? var.external_nat_ip_ids : try(aws_eip.nat[*].id, [])
+  nat_gateway_ips   = var.reuse_nat_ips ? var.external_nat_ip_ids : aws_eip.nat[*].id
 }
 
 resource "aws_eip" "nat" {