sftp-client(1) doesn't exist, link to the intended sftp(1) instead;

wrong link noticed by Andras Farkas;
while here, fix another typo on the same line, too

68.html

@@ -715,9 +715,9 @@ <h3>What's New</h3>
 avoid spurious error message when ssh-keygen creates files outside
 ~/.ssh
  	<li><a
-href="https://man.openbsd.org/sftp-client">sftp-client(1)</a>: fix
+href="https://man.openbsd.org/sftp.1">sftp(1)</a>: fix
 off-by-one error that caused sftp downloads to make one more
-concurrent request that desired. This prevented using <a
+concurrent request than desired. This prevented using <a
 href="https://man.openbsd.org/sftp">sftp(1)</a> in unpipelined
 request/response mode, which is useful when debugging.
  	<li><a href="https://man.openbsd.org/ssh">ssh(1)</a>, <a