Merge r1311174 from trunk:

Fix error handling in ap_scan_script_header_err_brigade() if there
is no EOS bucket in the brigade:

Also don't loop if there is a timeout when discarding the script output.

Thanks to Edgar Frank for the analysis.

PR: 48272 (partial fix)

Submitted by: sf
Reviewed/backported by: jim


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1331414 13f79535-47bb-0310-9956-ffa450edef68