Add TRUSTED_PROXY_IP option

[jeremiahlee]

Mastodon v4.2.9 started performing stricter checks to prevent client IP address spoofing. This environmental variable is required for use behind reverse proxy servers.

[timetinytim]

Good call, thank you!
@jeremiahlee Would you mind adding something in the values.yaml file indicating that this is something people can set? Something like:

  # Tells the Mastodon web and streaming processes which IPs act as your trusted reverse proxy
  # More info: https://docs.joinmastodon.org/admin/config/#trusted_proxy_ip
  trusted_proxy_ip:

[jeremiahlee]

@timetinytim Good catch. I accidentally left that file out of my commit. Updated.