Update README.ldap file for Windows build instructions.

PR:
Obtained from:
Submitted by:	Andre Schild <A.Schild@aarboard.ch>
Reviewed by:


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@97157 13f79535-47bb-0310-9956-ffa450edef68