How do I skip loading of Rails initializers when running a rake task?

My rails app has a website crawler that loads the authentication credentials that the crawler uses in a rails initializer in config/initializers. The initializer loads the authentication by calling a model method in SiteLogin model.

When I run rake db:migrate to create the SiteLogin model table it fails because the initializer expects the database table to already exist. I can simply comment out the code in my initializer, run the migration to create the table then uncomment the initializer code and not worry about the problem.

Problem is, I'm using Capistrano to deploy and this would mean that I'd have to deploy first without the initializer code to run the migration then deploy again with the initializer code. Is there a better way of doing this or is my approach totally wrong in this case.

Here's some code sample to better explain my case:

# config/initializers/site_crawler_init.rb
SiteCrawler.setup do |config|
  config.hostname = "www.example.com"
end

# model/site_crawler.rb
class SiteCrawler
  ...
  class << self
    attr_accessor :configuration

    def setup
      self.configuration ||= Configuration.new
      yield(configuration)
    end
  end

  class Configuration

    attr_accessor :hostname, :login_credentials

    def initialize
      @login_credentials = SiteLogin.admin_user
      ...
    end
  end
end