fix: Fix the condition of the logical operators of master_user_name and master_user_password (#4)

Author: sshcokr

main.tf

@@ -46,8 +46,8 @@ resource "aws_opensearch_domain" "this" {
 
         content {
           master_user_arn      = try(master_user_options.value.master_user_arn, null) == null ? try(master_user_options.value.master_user_arn, data.aws_iam_session_context.current[0].issuer_arn) : null
-          master_user_name     = try(master_user_options.value.master_user_name, null) == null ? try(master_user_options.value.master_user_name, null) : null
-          master_user_password = try(master_user_options.value.master_user_password, null) == null ? try(master_user_options.value.master_user_password, null) : null
+          master_user_name     = try(master_user_options.value.master_user_arn, null) == null ? try(master_user_options.value.master_user_name, null) : null
+          master_user_password = try(master_user_options.value.master_user_arn, null) == null ? try(master_user_options.value.master_user_password, null) : null
         }
       }
     }