Do not allow to list folders over sftp the user has no access to

proftpd.conf

@@ -24,7 +24,7 @@ ListOptions                	"-l"
 
 DenyFilter			\*.*/
 
-# Use this to jail all users in their homes 
+# Use this to jail all users in their homes
 # DefaultRoot			~
 
 # Users require a valid shell listed in /etc/shells to login.
@@ -65,7 +65,7 @@ Ratios off
 
 # Delay engine reduces impact of the so-called Timing Attack described in
 # http://www.securityfocus.com/bid/11430/discuss
-# It is on by default. 
+# It is on by default.
 <IfModule mod_delay.c>
 DelayEngine on
 </IfModule>
@@ -121,3 +121,6 @@ SFTPCompression delayed
 RequireValidShell off
 </IfModule>
 
+<Directory />
+  HideNoAccess yes
+</Directory>