Disable the encfs error message

Ths first line ('... boolean true') is needed to trick debian-cd into
believing that the type of the question is a boolean.

Otherwise debian-cd will think that the question doesn't exist, probably
because it doesn't know the type, probably because there's no type to
start with (this is an error message, not a question).

FTR, without the first line, it fails with:

  2022-08-04 10:05:37,846 DEBUG Checking configuration...
  error: Cannot find a question for encfs/security-information
  2022-08-04 10:05:38,016 ERROR preseed file invalid:
    <<LBDIR>>/simple-cdd/profiles/kali.preseed

kali-config/common/includes.installer/preseed.cfg

@@ -48,6 +48,10 @@ d-i apt-setup/cdrom/set-first boolean false
 # Disable popularity-contest
 popularity-contest popularity-contest/participate boolean false
 
+# Disable the encfs error message
+encfs encfs/security-information boolean true
+encfs encfs/security-information seen true
+
 # Random other questions
 console-setup console-setup/charmap47 select UTF-8
 samba-common samba-common/dhcp boolean false