KNOWN_BUGS: FTPS upload, FileZilla, GnuTLS and close_notify

Closes #11383

docs/KNOWN_BUGS

@@ -64,6 +64,7 @@ problems may have been fixed or changed somewhat since this was written.
  7.2 Implicit FTPS upload timeout
  7.3 FTP with NOBODY and FAILONERROR
  7.4 FTP with ACCT
+ 7.5 FTPS upload, FileZilla, GnuTLS and close_notify
  7.11 FTPS upload data loss with TLS 1.3
  7.12 FTPS directory listing hangs on Windows with Schannel
 
@@ -401,6 +402,13 @@ problems may have been fixed or changed somewhat since this was written.
  thus fails to issue the correct command:
  https://curl.se/bug/view.cgi?id=635
 
+7.5 FTPS upload, FileZilla, GnuTLS and close_notify
+
+ An issue where curl does not send the TLS alert close_notify, which triggers
+ the wrath of GnuTLS in FileZilla server, and a FTP reply 426 ECONNABORTED.
+
+ https://github.com/curl/curl/issues/11383
+
 7.11 FTPS upload data loss with TLS 1.3
 
  During FTPS upload curl does not attempt to read TLS handshake messages sent