If a request fails and the client will be redirected to another URL

If a request fails and the client will be redirected to another URL
due to ErrorDocument, see if we need to drop the connection after
sending the 302 response.  This fixes a problem where Apache treated
the body of the failed request as the next request on a keepalive
connection.  The subsequent 501 error sent to the browser prevented
some browsers from fetching the error document.

Reviewed by:  roy, jim

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@101486 13f79535-47bb-0310-9956-ffa450edef68