• 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.
  Added a test case to trigger this and verify correct behaviour.