fixin.me/app/controllers/user/profiles_controller.rb

class User::ProfilesController < Devise::RegistrationsController
  def destroy
    if current_user.sole_admin?
      redirect_back fallback_location: edit_user_registration_path,
        alert: t(".sole_admin")
      return
    end
    super
  end

  protected

  def build_resource(hash = {})
    super
    # Skip the email confirmation step when the admin has enabled this option
    # via the web setup wizard (stored as the "skip_email_confirmation" Setting).
    # The account becomes active immediately so the user can sign in right after
    # registering.
    resource.skip_confirmation! if Setting.get("skip_email_confirmation") == "true"
  end

  def update_resource(resource, params)
    # Based on update_with_password()
    if params[:password].blank?
      params.delete(:password)
      params.delete(:password_confirmation) if params[:password_confirmation].blank?
    end

    result = resource.update(params)
    resource.clean_up_passwords
    result
  end

  def after_inactive_sign_up_path_for(resource)
    new_user_session_path
  end
end