server {
    listen 443;
    server_name test3.de;
    ssl on;
    ssl_certificate /etc/ssl/crt/vinci-u18iptables.crt;
    ssl_certificate_key /etc/ssl/crt/vinci-u18iptables.key;

location / {
    proxy_pass http://test2.de;
    proxy_redirect off;
    proxy_set_header Host $host;
    proxy_set_header X-Forwarded-Host $host;
    proxy_set_header X-Forwarded-Server $host;
    proxy_set_header X-Real-IP $remote_addr;
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_connect_timeout 60;
    proxy_read_timeout 60;
    proxy_send_timeout 60;
    send_timeout 60;
    proxy_http_version 1.1;
    proxy_set_header Connection "";
  }
}

RemoteIPHeader X-Forwarded-For
LogFormat "%v:%p %a %l %u %t "%r" %>s %O referer: "%{Referer}i" "%{User-Agent}i"" vhost_combined
LogFormat "%a %l %u %t "%r" %>s %O referer: "%{Referer}i" "%{User-Agent}i"" combined
LogFormat "%a %l %u %t "%r" %>s %O" common
LogFormat "%{Referer}i -> %U" referer
LogFormat "%{User-agent}i" agent

<VirtualHost *:80>
    ServerName test2.de
    ServerAdmin webmaster@localhost
    DocumentRoot /var/www/html
    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined
</VirtualHost>

192.168.80.53 - - [23/Jan/2019:14:47:38 +0000] "GET /info.php HTTP/1.1" 200 21788 referer: "-" "Mozilla/5.0 (X11; Linux x86_64)
AppleWebKit/537.36 (KHTML, like Gecko) Ubuntu Chromium/71.0.3578.98
Chrome/71.0.3578.98 Safari/537.36"