Only do grub setup on first boot

src/freedombone-image-customise

 
     if [[ $ARCHITECTURE == 'qemu'* || $ARCHITECTURE == 'amd64' || $ARCHITECTURE == 'x86_64' || $ARCHITECTURE == 'i686' || $ARCHITECTURE == 'i386' ]]; then
         chroot "$rootdir" apt-get -yq install grub2
-        sed -i 's|GRUB_CMDLINE_LINUX_DEFAULT=.*|GRUB_CMDLINE_LINUX_DEFAULT="quiet ifnames=0 slub_debug=FZP slab_nomerge page_poison=1"|g' $rootdir/etc/default/grub
-        chroot "$rootdir" update-grub
     fi
 
     chroot "$rootdir" apt-get -yq install locales locales-all debconf
 if [[ $ARCHITECTURE == 'qemu'* || $ARCHITECTURE == 'i386' || $ARCHITECTURE == 'i686' || $ARCHITECTURE == 'amd64' || $ARCHITECTURE == 'x86_64' ]]; then
     chroot "$rootdir" apt-get install -y cryptsetup zsh pinentry-curses iotop bc
     chroot "$rootdir" apt-get install -y grub2 hostapd
-    sed -i 's|GRUB_CMDLINE_LINUX_DEFAULT=.*|GRUB_CMDLINE_LINUX_DEFAULT="quiet ifnames=0 slub_debug=FZP slab_nomerge page_poison=1"|g' $rootdir/etc/default/grub
-    chroot "$rootdir" update-grub
 fi
 
 sed -i "s|#host-name=.*|host-name=${PROJECT_NAME}|g" $rootdir/etc/avahi/avahi-daemon.conf