Disable sendfile by default, as discussed at

http://mail-archives.apache.org/mod_mbox/httpd-dev/201007.mbox/<4C4355EE.2060605@rowe-clan.net>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@992689 13f79535-47bb-0310-9956-ffa450edef68