Make the logging in mod_proxy_fcgi more consistent.

* modules/proxy/mod_proxy_fcgi.c
  (fcgi_do_request): Log errors as APLOG_ERR.
  (proxy_fcgi_handler): Log debug info as APLOG_DEBUG.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@408520 13f79535-47bb-0310-9956-ffa450edef68