zammad/db/migrate/20170119000001_login_email_length_650.rb

class LoginEmailLength650 < ActiveRecord::Migration[4.2]
  def up

    # return if it's a new setup
    return if !Setting.find_by(name: 'system_init_done')

    change_column(:users, :login, :string, limit: 255)
    change_column(:users, :email, :string, limit: 255)
  end
end