Security hardening for ghaf logging server

[joinemm]

• Grafana available at https://ghaflogs.vedenemo.dev, requires login to view.
• Loki push endpoint available at https://loki.ghaflogs.vedenemo.dev, behind basic auth username and password.
• Access using insecure ip:port and http no longer possible, firewall gaps closed.
• Applied security hardening options for Grafana.

[vunnyso]

Tested with tiiuae/ghaf#700 on Lenovo X1, works fine.