Added documentation for the support of LDAP StartTLS connection settings.

https://community.igniterealtime.org/thread/48391
https://igniterealtime.org/issues/browse/OF-66Signed-off-by: Sebastian Wendel <swendel-git@sourceindex.de>

documentation/docs/ldap-guide.html

@@ -259,7 +259,9 @@ servers, some of which are detailed below:
             you
             enable SSL connections, the LDAP server port number most likely should be changed to
             636.</li>
-
+    <li>ldap.startTlsEnabled -- a value of "true" to enable StartTLS connections to your LDAP server. If
+            you enable StartTLS connections, the LDAP server port number most likely should be changed to
+            389.</li>
     <li>ldap.initialContextFactory -- the name of the class that should be used as an initial
         context
         factory. if this value is not specified, "com.sun.jndi.ldap.LdapCtxFactory" will be used
@@ -517,4 +519,4 @@ clients that support the XMPP vCard extension. First, enable the provider:</p>
 </div>
 
 </body>
-</html>
+</html>
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