mod_isapi: Fix an issue where HSE_REQ_DONE_WITH_SESSION notification
  is received before the HttpExtensionProc() returns HSE_STATUS_PENDING.
  [John DeSetto <jdesetto@radiantsystems.com>, William Rowe]

PR: 11918


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@97467 13f79535-47bb-0310-9956-ffa450edef68