edit zone only if zonage feature enabled

app/views/administrateurs/procedures/_informations.html.haml

@@ -13,10 +13,11 @@
   %span.mandatory *
 = f.text_area :description, rows: '6', placeholder: 'Description de la démarche, destinataires, etc. ', class: 'form-control'
 
-= f.label :zone do
-  = t('zone', scope: 'activerecord.attributes.procedure')
-  %span.mandatory *
-= f.select :zone_id, grouped_options_for_zone
+- if Flipper.enabled? :zonage
+  = f.label :zone do
+    = t('zone', scope: 'activerecord.attributes.procedure')
+    %span.mandatory *
+  = f.select :zone_id, grouped_options_for_zone
 
 %h3.header-subsection Logo de la démarche
 = image_upload_and_render f, @procedure.logo