* modules/generators/mod_cgi.c (cgi_bucket_read): Log a specific error

if a timeout occurs from a blocking read; more helpful than a generic
"apr_bucket_read failed" error from some higher-up filter.


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@189560 13f79535-47bb-0310-9956-ffa450edef68