Only update timezone on address change

I feel that your version makes the method less readable. What's the clearest way to communicate that there are 3 pre-conditions that need to be met before updating the time zone? The version below is a bit less concise, but is very readable.

```ruby
  def update_contact_timezone
    return unless primary_mailing_address?
    return unless (changed & %w(street city state country primary_mailing_address)).present?
    return unless addressable.respond_to?(:set_timezone)

    addressable.set_timezone
  end
```