Revert "SECURITY: Fix XSS on unsubscribed page."

This reverts commit 190558db9d.

app/controllers/email_controller.rb

@@ -110,7 +110,6 @@ class EmailController < ApplicationController
 
   def unsubscribed
     @email = params[:email]
-    raise Discourse::NotFound if !User.find_by_email(params[:email])
     @topic = Topic.find_by(id: params[:topic_id].to_i) if params[:topic_id]
   end
 

app/controllers/invites_controller.rb

@@ -96,7 +96,6 @@ class InvitesController < ApplicationController
 
     guardian.ensure_can_invite_to_forum!(groups)
     topic = Topic.find_by(id: params[:topic_id])
-    guardian.ensure_can_see_topic?(topic)
     group_ids = groups.map(&:id)
 
     invite_exists = Invite.where(email: params[:email], invited_by_id: current_user.id).first

spec/requests/email_controller_spec.rb

@@ -1,13 +0,0 @@
-require 'rails_helper'
-
-RSpec.describe EmailController do
-  describe '#unsubscribed' do
-    describe 'when email is invalid' do
-      it 'should return the right response' do
-        get '/email/unsubscribed', params: { email: 'somerandomstring' }
-
-        expect(response.status).to eq(404)
-      end
-    end
-  end
-end