Let Nginx listen to HTTPS over IPv6

[gaitjan]

I had to add a line to the Nginx-config to let Nginx listen to HTTPS over IPv6:
In the file
/usr/local/etc/nginx/conf.d/nextcloud.https.conf.template
below the line
listen 443 ssl http2;
I added
listen [::]:443 ssl http2;
which at last got me a 100% score at internet.nl