Either you are trying to access an unknown server or you are trying to reach a server via htts that isn't configured for secure access.
SCRIPT_URI: https://nats-www.informatik.uni-hamburg.de/index.shtml
HTTP_HOST: nats-www.informatik.uni-hamburg.de
SERVER_NAME: nats-www.informatik.uni-hamburg.de
SERVER_ADDR: 134.100.9.78
REMOTE_ADDR: 216.73.216.31