fix: sg arn output breaks when providing security groups IDs (#67)

* fix: sg arn output

* fix

---------

Co-authored-by: Dmitrij Nikitenko <[email protected]>

outputs.tf

@@ -9,7 +9,7 @@ output "security_group_id" {
 }
 
 output "security_group_arn" {
-  value       = join("", module.aws_security_group[*].arn)
+  value       = module.aws_security_group.arn
   description = "The ARN of the created security group"
 }