merge this from 2.1-dev:

  Fix the inability to log errors like exec failure in
  mod_ext_filter/mod_cgi script children.  This was broken after
  such children stopped inheriting the error log handle.

Reviewed by: nd, jorton


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/APACHE_2_0_BRANCH@101778 13f79535-47bb-0310-9956-ffa450edef68