Fix reference link in FTPS and Shared SSLSession (#10858)

current it uses a regional suffix `.cz` , which can not be opened in my region,  however,  `.com` works for me.

Signed-off-by: Jiandong Ma <jiandong.ma.cn@gmail.com>

**Auto-cherry-pick to 7.0.x, 6.5.x**

Author: mjd507

src/reference/antora/modules/ROOT/pages/ftp/advanced-configuration.adoc

@@ -42,7 +42,7 @@ public class AdvancedFtpSessionFactory extends DefaultFtpSessionFactory {
 
 When using FTP over SSL or TLS, some servers require the same `SSLSession` to be used on the control and data connections.
 This is to prevent "`stealing`" data connections.
-See https://scarybeastsecurity.blogspot.cz/2009/02/vsftpd-210-released.html for more information.
+See https://scarybeastsecurity.blogspot.com/2009/02/vsftpd-210-released.html for more information.
 
 Currently, the Apache FTPSClient does not support this feature.
 See https://issues.apache.org/jira/browse/NET-408[NET-408].