Fix content for back link for edit route page

This was missed from #1789.

Update the link text for the back link to read "Back to question X’s
routes", to match the designs.

app/views/pages/conditions/edit.html.erb

@@ -1,6 +1,6 @@
 <%# TODO: route_position is hardcoded as 1 here because we know there are only two conditions. It will need to change in the future %>
 <% set_page_title(title_with_error_prefix(t('page_titles.routing_page_edit', question_position: condition_input.page.position, route_position: 1), condition_input.errors&.any?)) %>
-<% content_for :back_link, govuk_back_link_to(show_routes_path(condition_input.form.id, page_id: condition_input.page.id)) %>
+<% content_for :back_link, govuk_back_link_to(show_routes_path(condition_input.form.id, page_id: condition_input.page.id), t(".back_link", question_number: condition_input.page.position)) %>
 
 <div class="govuk-grid-row">
   <div class="govuk-grid-column-two-thirds">

config/locales/en.yml

@@ -1153,6 +1153,8 @@ en:
     conditions:
       delete:
         any_other_answer_warning: If you delete this route, the route for any other answer will also be deleted
+      edit:
+        back_link: Back to question %{question_number}’s routes
     delete:
       notification_banner:
         end_of_route: