Merge of /httpd/httpd/trunk:r1893359

Merge of /httpd/httpd/trunk:r1893359

  *) mod_md: fixed a bug in handling multiple parallel OCSP requests. These could
     run into an assertion which terminated (and restarted) the child process where
     the task was running. Eventually, all OCSP responses were collected, but not
     in the way that things are supposed to work.
     See also <https://bz.apache.org/bugzilla/show_bug.cgi?id=65567>.
     The bug was possibly triggered when more than one OCSP status needed updating
     at the same time. For example for several renewed certificates after a server
     reload.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1893360 13f79535-47bb-0310-9956-ffa450edef68