Enable remote census configuration when remote census is active

According to the feature setting["remote_census"]:
  - Display info to enable tab when remote_census feature is disabled.
  - Display all related setting to remote_census when feature is enabled

app/views/admin/settings/_remote_census_configuration_tab.html.erb

@@ -1,5 +1,11 @@
+<% if feature?(:remote_census) %>
   <h2><%= t("admin.settings.index.remote_census.title") %></h2>
 
   <%= render "settings_table", settings: @remote_census_general_settings %>
   <%= render "settings_table", settings: @remote_census_request_settings %>
   <%= render "settings_table", settings: @remote_census_response_settings %>
+<% else %>
+  <div class="callout primary">
+    <%= t("admin.settings.index.remote_census.how_to_enable") %>
+  </div>
+<% end %>

config/locales/en/admin.yml

@@ -1313,6 +1313,7 @@ en:
           title: Proposals dashboard
         remote_census:
           title: Remote Census configuration
+          how_to_enable: 'To configure remote census (SOAP) you must enable "Configure connection to remote census (SOAP)" on "Features" tab.'
       setting: Feature
       setting_actions: Actions
       setting_name: Setting

config/locales/es/admin.yml

@@ -1314,6 +1314,7 @@ es:
           title: Panel de progreso de propuestas
         remote_census:
           title: Configuración del Censo Remoto
+          how_to_enable: 'Para configurar la conexión con el Censo Remoto (SOAP) se debe activar "Configurar la conexión al censo remoto (SOAP)" en la pestaña "Funcionalidades".'
       setting: Funcionalidad
       setting_actions: Acciones
       setting_name: Configuración

spec/features/admin/settings_spec.rb

@@ -132,6 +132,35 @@ describe "Admin settings" do
 
   end
 
+  describe "Update Remote Census Configuration" do
+
+    scenario "Should not be able when remote census feature deactivated" do
+      Setting["feature.remote_census"] = nil
+      admin = create(:administrator).user
+      login_as(admin)
+      visit admin_settings_path
+      find("#remote-census-tab").click
+
+      expect(page).to have_content 'To configure remote census (SOAP) you must enable ' \
+                                   '"Configure connection to remote census (SOAP)" ' \
+                                   'on "Features" tab.'
+    end
+
+    scenario "Should be able when remote census feature activated" do
+      Setting["feature.remote_census"] = true
+      admin = create(:administrator).user
+      login_as(admin)
+      visit admin_settings_path
+      find("#remote-census-tab").click
+
+      expect(page).not_to have_content 'To configure remote census (SOAP) you must enable ' \
+                                       '"Configure connection to remote census (SOAP)" ' \
+                                       'on "Features" tab.'
+      Setting["feature.remote_census"] = nil
+    end
+
+  end
+
   describe "Skip verification" do
 
     scenario "deactivate skip verification", :js do