nginx: temporarily disable catalog for production

conf/nginx/server-base.conf.jnj

@@ -136,6 +136,10 @@ location ~ ^/v2 {
     client_max_body_size {{ maximum_layer_size }};
 }
 
+location /v2/_catalog {
+  return 400;
+}
+
 location ~ ^/v1 {
     # Setting ANY header clears all inherited proxy_set_header directives
     proxy_set_header X-Forwarded-For $proper_forwarded_for;