```ruby
#!/usr/bin/env ruby

require 'csv'

input = CSV.parse($stdin, headers: true).collect { |row|
  [row['Old Url'], (row['New Url'] == "" ? nil : row['New Url']), row['Status']]
}

folded_csv = CSV.generate do |csv|
  csv << ["Old Url", "New Url", "Status"]
  input.each do |row|
    csv << row.map {|x| x.respond_to?(:strip) ? x.strip : nil }
  end
end

puts folded_csv
```

Remove inaccurate reference to 'folded'
user
```ruby
#!/usr/bin/env ruby

require 'csv'

input = CSV.parse($stdin, headers: true).collect { |row|
  [row['Old Url'], (row['New Url'] == "" ? nil : row['New Url']), row['Status']]
}

output_csv = CSV.generate do |csv|
  csv << ["Old Url", "New Url", "Status"]
  input.each do |row|
    csv << row.map {|x| x.respond_to?(:strip) ? x.strip : nil }
  end
end

puts output_csv
```
assistant