* proxy_http fix: mod_proxy hangs when both KeepAlive and
  ProxyErrorOverride are enabled, and a non-200 response without a
  body is generated by the backend server.

Submitted by: Graham Wiseman <gwiseman fscinternet.com>, Richard Reiner
Reviewed by: stoddard, nd, jerenkrantz, rederpj


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@102465 13f79535-47bb-0310-9956-ffa450edef68