Merge r583813 from trunk:

* modules/proxy/mod_proxy_http.c (ap_proxy_http_register_hook): Fix
  apr_pool_cleanup_register() invocation added in r583202, which was
  causing every apr_proc_create() call to segfault.

Submitted by: jorton
Reviewed by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.2.x@584821 13f79535-47bb-0310-9956-ffa450edef68