remove http compat from docs

Signed-off-by: kim (grufwub) <grufwub@gmail.com>

docs/USAGE.md

@@ -22,8 +22,6 @@ gophi [args]
       -cgi-dir            CGI scripts directory (empty to disable)
       -max-cgi-time       Max CGI script execution time
       -safe-path          CGI environment safe PATH variable
-      -http-compat-cgi    Enable HTTP compatibility for CGI scripts by stripping headers
-      -http-prefix-buf    Buffer size used for stripping HTTP headers
 
       -user-dir           User subdir for personal server space