removed TLSv1.3 because nginx 1.13 or higher and ubuntu 18.04 versions are required to run TLSv1.3

scripts/setup_webserver.sh

@@ -149,8 +149,8 @@ http {
   set_real_ip_from   127.0.0.1;
   real_ip_header      X-Forwarded-For;
   #ssl_protocols TLSv1 TLSv1.1 TLSv1.2; # Dropping SSLv3, ref: POODLE
-  #upgrading to TLSv1.2, TLSv1.3 and droping 1 & 1.1
-  ssl_protocols TLSv1.2 TLSv1.3;
+  #upgrading to TLSv1.2 and droping 1 & 1.1
+  ssl_protocols TLSv1.2;
   #ssl_prefer_server_ciphers on;
   #adding ssl ciphers
   ssl_ciphers ECDHE-RSA-AES256-GCM-SHA512:DHE-RSA-AES256-GCM-SHA512:ECDHE-RSA-AES256-GCM-SHA384:DHE-RSA-AES256-GCM-SHA384:ECDHE-RSA-AES256-SHA384;