Bug 2030: Timeout while uploading files to some FTP server using TLS 1.3

https://winscp.net/tracker/2030
(cherry picked from commit f7064be2ce0d615c1ec2208f198b36a55dc5384d)

Source commit: 09c9056802bfb469384455179679d4d028ef4393

source/filezilla/AsyncSslSocketLayer.cpp

@@ -1005,15 +1005,6 @@ BOOL CAsyncSslSocketLayer::ShutDown(int nHow /*=sends*/)
     }
 
     int res = SSL_shutdown(m_ssl);
-    if (res == 0)
-    {
-      res = SSL_shutdown(m_ssl);
-      // While this should not be necessary, with IIS we get timeout otherwise
-      if (SSL_version(m_ssl) <= TLS1_2_VERSION)
-      {
-        res = 0;
-      }
-    }
     if (res >= 0)
     {
       if (ShutDownComplete())