allow skipping discarding numbers in unslugify

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
do not break old sites

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>
missing one instance

Signed-off-by: Chris “Kwpolska” Warrick <kwpolska@gmail.com>