default_url is always hit with a HTTP request

Problem

Using Paperclip 6.1.0.

Whenever I save a model record that has a set image to it, the default_url is hit with a URL request. This is problematic if a developer who is locally testing data doesn't have access to the internet.

## model used 
class Image < ActiveRecord::Base
PAPERCLIP_CONFIG = {
  storage: :s3,
  s3_protocol: :https,
  bucket:  'xxx',
  region: 'us-east-1',
  s3_region: 'us-east-1',
  s3_credentials:  {
    access_key_id:  'xxx',
    secret_access_key:  'xxx'
  },
  path: ':class/:id/:basename.:extension'
}

  has_attached_file :image_asset, PAPERCLIP_CONFIG.merge(
    {
      styles: {
        small: ["152x198"],
        large: ["500x700#"],
        larger: ["616x732"],
      },
      path: ":class/:id/:style/:basename.:extension"
    })
end

## code
image_path = Rails.root.join('app', 'assets', 'images', 'Default.jpg')
image_file = File.new(image_path)

image = Image.new(image_asset: image_file) 
image.save! 

What I Expect To Happen

If I'm creating a new image with a pre-determined asset, I shouldn't expect my default_url to be hit with a HTTP request.