because it may block when flushing data to the client.
From the listener thread, do a lingering close without flushing. This is
OK because we only do this if there has been an error during write
completion or if our send buffers are empty because we are in keep-alive.
PR: 52229
git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1294356 13f79535-47bb-0310-9956-ffa450edef68