Default to USE_FCNTL_SERIALIZED_ACCEPT on HPUX to properly handle

multiple Listen directives.

PR: 872
Obtained from:
Submitted by:
Reviewed by:	Paul Sutton, Jim Jagielski


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@79529 13f79535-47bb-0310-9956-ffa450edef68