proxy_cache_path levels

[yolabingo]

Correction of a minor error in the previous message:

# levels=1:1:1 also provides 16^3 = 4096 directories, but in 3 levels 
proxy_cache_path /data/nginx/cache levels=1:1:1; 
/data/nginx/cache/b/1/5/d7b6e5978e3f042f52e875005925e51b

Posted at Nginx Forum: https://forum.nginx.org/read.php?2,2450,273133#msg-273133