Fix prefix in nginx set_real_ip_from to only use private address range

[Nothing4You]

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[Nothing4You]

If all private IPv4 RFC 1918 private IPs should be accepted then this could be extended to also take 10.0.0.0/8 and 192.168.0.0/16.

[codyro]

If all private IPv4 RFC 1918 private IPs should be accepted then this could be extended to also take 10.0.0.0/8 and 192.168.0.0/16.

I believe Docker uses the 172.17.0.0/16 by default, which might explain why this was configured this way.

Podman uses 10.88.0.0/16 by default, so we should at least add that range as well, although I can see the argument for doing the full /8.