Add defines for USE_FLOCK_SERIALIZED_ACCEPT and

SINGLE_LISTEN_UNSERIALIZED_ACCEPT to NetBSD/OpenBSD section
to allow serialized accept for multiport listens.
Also fixed a misplaced #endif that would skip several defines
if DEFAULT_GROUP was overridden.

PR: 3120
Submitted by:	Roy Fielding, Curt Sampson <cjs@portal.ca>


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@82467 13f79535-47bb-0310-9956-ffa450edef68