Gracefully closes SSL session.
This method causes
TElSimpleSSLClient to gracefully close SSL session.
Call this method after application has finished using the SSL/TLS session.
If SSL is not enabled (Enabled property is set to false), TElSimpleSSLClient does nothing and returns immediately.
If Silent parameter is set to False, TElSimpleSSLClient sends closing SSL notification to server.
Set this parameter to True to prevent sending of notification packet. In this case the session can't be resumed later.
Default value is False.