The scan dialog now shows a single 'Ignore contents of files:' label and a
two-column checkbox grid with just the file names (the per-row 'Ignore
contents of ...' prefix was redundant). Drop the now-unused i18n key and
add the new label (RU: 'Игнорировать содержимое файлов:'). Help docs
updated. SW cache v67 -> v68.