Merge r1242798 from trunk:

* modules/proxy/mod_proxy_http.c (ap_proxy_http_process_response):
  Treat EAGAIN as an error for a blocking read from the input filter
  stack.

Submitted by: jorton
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1368447 13f79535-47bb-0310-9956-ffa450edef68