fix vpc az_count value

Author: Max Glotov

terraform/modules/aws-vpc/main.tf

@@ -1,5 +1,5 @@
 locals {
-  az_count         = length(var.azs)
+  az_count         = length(var.azs) - 1
   cidr_subnets     = [for cidr_block in cidrsubnets(var.cidr, 2, 2, 2, 2) : cidrsubnets(cidr_block, 4, 4, 4, 4)]
   private_subnets  = chunklist(local.cidr_subnets[0], local.az_count)[0]
   public_subnets   = chunklist(local.cidr_subnets[1], local.az_count)[0]