Merge r1739201 from trunk:

http: Respond with "408 Request Timeout" when a timeout occurs while
reading the request body.

Submitted by: ylavic
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1768079 13f79535-47bb-0310-9956-ffa450edef68