Unassigned `$ramdisk_dir`

[HugoFlorentino]

The tool has an option for using ramdisk, if availale. However if ramdisk is not installed, an error appears when trying to generate the script:

  if mount | grep -q "$ramdisk_dir" ; then
                      ^----------^ SC2154: ramdisk_dir is referenced but not assigned.```

[HugoFlorentino]

I solved this error modifying the insert_runscript_functions block with this:

  if [ -n "${use_ramdisk+x}" ]; then
    insert_runscript_function_unmount_ramdisk
  fi