KNOWN_BUGS: "FTPS needs session reuse"

Closes #4654
diff --git a/docs/KNOWN_BUGS b/docs/KNOWN_BUGS
index fe8d59d..8df986c 100644
--- a/docs/KNOWN_BUGS
+++ b/docs/KNOWN_BUGS
@@ -78,6 +78,7 @@
  7.7 FTP and empty path parts in the URL
  7.8 Premature transfer end but healthy control channel
  7.9 Passive transfer tries only one IP address
+ 7.10 FTPS needs session reuse
 
  8. TELNET
  8.1 TELNET and time limitations don't work
@@ -588,6 +589,14 @@
 
  See https://github.com/curl/curl/issues/1508
 
+7.10 FTPS needs session reuse
+
+ When the control connection is reused for a subsequent transfer, some FTPS
+ servers complain about "missing session reuse" for the data channel for the
+ second transfer.
+
+ https://github.com/curl/curl/issues/4654
+
 8. TELNET
 
 8.1 TELNET and time limitations don't work