DISABLE_BEACON is not obeyed by the backend

[xixixao]

DISABLE_BEACON is only obeyed by the docker compose setup, not by the backend itself. I guess the error message might be hinting at this with:

You can disable this telemetry by setting the --disable-beacon flag or the DISABLE_BEACON environment variable if you are self-hosting using the Docker image.

but it's confusing (like what is "the Docker image" in that sentence?). It'd be better if the backend binary itself read the value from the env var.

[nipunn1313]

yep! Agreed! Little bit confusing.
If someone wants to grab this one - it seems pretty doable. Have both the env var and the command line flag - if either is set, then have the backend obey.

[nipunn1313]

Fixed - thanks @STAR-173