Trusted proxies issue: configuration behind Haproxy

[sm8ps]

I hope it is okay to write a solution instead of an issue here. After hours of searching here and everywhere else on the internet I finally stumbled over a solution that may help others. My problem was that all how-tos seem use https:// followed by a DNS-name for NEXTCLOUD_URL. It took me quite some time of staring at it before I realized that there are two knobs that can be turned separately.

My Nextcloud server is behind a HA proxy that does TLS-termination. So in hindsight it is pretty obvious that NEXTCLOUD_URL should be given with http://. Just as suggested in the troubleshooting part of the readme it took the internal IP-address of the server to make it all work.

Thanks a lot for providing this useful piece of software!