chore: use drop-in fragment for pwquality.conf

Solves issue #6

debian/postinst

@@ -3,14 +3,6 @@
 
 set -e
 
-CONF_FILE="/etc/security/pwquality.conf"
-
-yd_update_keyval() { # file key value...
-    local file="$1" key="$2" ; shift 2
-    # delete line starting with key then append to the end
-    sed -e "/^[ \t]*$key[ \t]\=/d" -e "\$a$key = $*" -i "$file"
-}
-
 case "$1" in
     configure)
         # Enable GDM customization
@@ -65,21 +57,6 @@ case "$1" in
     ;;
 esac
 
-# Min size of password
-yd_update_keyval "$CONF_FILE" "minlen" "10"
-
-# Lowercase char (-1 => min 1 char)
-yd_update_keyval "$CONF_FILE" "lcredit" "-1" 
-
-# Uppercase char (-1 => min 1 char)
-yd_update_keyval "$CONF_FILE" "ucredit" "-1"
-
-# Decimal char (-1 => min 1 char)
-yd_update_keyval "$CONF_FILE" "dcredit" "-1"
-
-# Other char (-1 => min 1 char)
-yd_update_keyval "$CONF_FILE" "ocredit" "-1"
-
 # dh_installdeb will replace this with shell code automatically
 # generated by other debhelper scripts.