OpenBSD doesn't need -ldbm.

PR:
Obtained from:
Submitted by:	Bob Beck <beck@bofh.ucs.ualberta.ca>
Reviewed by:


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/1.3.x@80614 13f79535-47bb-0310-9956-ffa450edef68