fix nginx vhiost domain

contrib/nginx/sites-available/zammad.conf

@@ -14,7 +14,7 @@ upstream zammad-websocket {
 
 server {
     listen 80;
-    server_name zammad.intdmz.h1.mdd zammad.magix-support.net;
+    server_name zammad.example.com;
     root /opt/zammad/public;
 
     access_log /var/log/nginx/zammad.access.log;