If an ErrorDocument CGI script is used to respond to an error

generated by another CGI script which has already read the message
body of the request, the server would block trying to read the
message body again.

I thought this problem was fixed by removing the Content-Length header
field in mod_cgi, but that only fixed it for internal redirects.
So, I have restored the previously tested and verified fix which is
specific to ErrorDocument.

Submitted by: Rob Hartill
Reviewed by: Roy Fielding


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@78073 13f79535-47bb-0310-9956-ffa450edef68