Remove useless test header setup for emails

Once upon a time we needed a helper to set the `from` header of emails.
This is now set in the ApplicationMailer and not necessary any more.

spec/system/admin/enterprise_roles_spec.rb

@@ -8,7 +8,6 @@ describe '
 ' do
   include AuthenticationHelper
   include WebHelper
-  include OpenFoodNetwork::EmailHelper
 
   context "as a site administrator" do
     before { login_to_admin_section }
@@ -150,7 +149,6 @@ create(:enterprise)
       end
 
       xit "can invite unregistered users to be managers" do
-        setup_email
         find('a.button.help-modal').click
         expect(page).to have_css '#invite-manager-modal'
 

spec/system/admin/users_spec.rb

@@ -8,7 +8,6 @@ describe "Managing users" do
 
   context "as super-admin" do
     before do
-      setup_email
       login_as_admin
     end
 

spec/system/consumer/account/settings_spec.rb

@@ -15,7 +15,6 @@ describe "Account Settings" do
     end
 
     before do
-      setup_email
       login_as user
       visit "/account"
       find("a", text: /Account Settings/i).click

spec/system/consumer/authentication_spec.rb

@@ -5,7 +5,6 @@ require 'system_helper'
 describe "Authentication" do
   include AuthenticationHelper
   include UIComponentHelper
-  include OpenFoodNetwork::EmailHelper
 
   describe "login" do
     let(:user) { create(:user, password: "password", password_confirmation: "password") }

spec/system/consumer/shopping/orders_spec.rb

@@ -4,7 +4,6 @@ require 'system_helper'
 
 describe "Order Management" do
   include AuthenticationHelper
-  include OpenFoodNetwork::EmailHelper
 
   describe "viewing a completed order" do
     let!(:distributor) { create(:distributor_enterprise) }
@@ -148,9 +147,6 @@ describe "Order Management" do
     end
 
     context "when the distributor allows changes to be made to orders" do
-      before do
-        setup_email
-      end
       before do
         order.distributor.update(allow_order_changes: true)
       end

spec/system/consumer/user_password_spec.rb

@@ -4,7 +4,6 @@ require "system_helper"
 
 describe "User password confirm/reset page" do
   include UIComponentHelper
-  include OpenFoodNetwork::EmailHelper
 
   let(:email) { "test@example.org" }
   let(:user) { Spree::User.create(email: email, unconfirmed_email: email, password: "secret") }