Update "reply" notification email to add unsubscribe link

We modified the link that previously redirected us to the "My content"
page to redirect us to the new page for managing subscriptions.

We also adapted the existing generic text by adding a description of
the related notification.

app/mailers/mailer.rb

@@ -20,6 +20,7 @@ class Mailer < ApplicationMailer
   def reply(reply)
     @email = ReplyEmail.new(reply)
     @email_to = @email.to
+    manage_subscriptions_token(@email.recipient)
 
     with_user(@email.recipient) do
       mail(to: @email_to, subject: @email.subject) if @email.can_be_sent?

app/views/mailer/reply.html.erb

@@ -18,6 +18,13 @@
   </div>
 
   <p style="font-family: 'Open Sans','Helvetica Neue',arial,sans-serif;font-size: 12px;font-weight: normal;line-height: 20px;">
-    <%= t("mailers.config.manage_email_subscriptions") %> <%= link_to t("account.show.title"), account_url, style: "color: #2895F1; text-decoration:none;" %>
+    <%= sanitize(t("mailers.config.unsubscribe_text",
+      notifications: link_to(
+        t("mailers.config.notifications_link"),
+        edit_subscriptions_url(token: @token),
+        style: "color: #2895F1; text-decoration: none;"
+      ),
+      notification: User.human_attribute_name(:email_on_comment_reply)
+    )) %>
   </p>
 </td>

spec/system/admin/system_emails_spec.rb

@@ -176,6 +176,9 @@ describe "System Emails" do
       expect(page).to have_content reply.body
 
       expect(page).to have_link "Let's do...", href: comment_url(reply, host: app_host)
+      expect(page).to have_link("Notifications",
+                                href: edit_subscriptions_url(token: user.subscriptions_token,
+                                                             host: app_host))
     end
 
     scenario "#direct_message_for_receiver" do

spec/system/emails_spec.rb

@@ -198,8 +198,9 @@ describe "Emails" do
       expect(email).to deliver_to(user)
       expect(email).not_to have_body_text(debate_path(debate))
       expect(email).to have_body_text(comment_path(Comment.last))
-      expect(email).to have_body_text("To stop receiving these emails change your settings in")
+      expect(email).to have_body_text("To unsubscribe from these emails, visit")
-      expect(email).to have_body_text(account_path)
+      expect(email).to have_body_text(edit_subscriptions_path(token: user.subscriptions_token))
+      expect(email).to have_body_text('and uncheck "Notify me by email when someone replies to my comments"')
     end
 
     scenario "Do not send email about own replies to own comments" do
@@ -469,8 +470,9 @@ describe "Emails" do
       expect(email).to deliver_to(user1)
       expect(email).not_to have_body_text(poll_path(poll))
       expect(email).to have_body_text(comment_path(Comment.last))
-      expect(email).to have_body_text("To stop receiving these emails change your settings in")
+      expect(email).to have_body_text("To unsubscribe from these emails, visit")
-      expect(email).to have_body_text(account_path)
+      expect(email).to have_body_text(edit_subscriptions_path(token: user1.subscriptions_token))
+      expect(email).to have_body_text('and uncheck "Notify me by email when someone replies to my comments"')
     end
   end