packaging: drop DEBHELPER comment in pre-install script

Author: cognifloyd

packaging/deb/scripts/pre-install.sh

@@ -49,9 +49,4 @@ case "$1" in
         ;;
 esac
 
-# dh_installdeb will replace this with shell code automatically
-# generated by other debhelper scripts.
-
-#DEBHELPER#
-
 exit 0