Correct config-file options for enabling HTTP API are hard to find
For xmrig-proxy, documentation of the newer "http"  section of config.json is ONLY found here:  https://github.com/xmrig/xmrig/issues/1007

ALSO: The https://config.xmrig.com/proxy site generates a wrong configuration.  API access does not work because the config is using the old "api" options in the config.json file

https://github.com/xmrig/xmrig-proxy/wiki/API - this doc is wrong and should be updated to show a working HTTP API config
