fix(geopoint_field): no geoportail link without coordinates

app/fields/geopoint_field.rb

@@ -8,4 +8,8 @@ class GeopointField < Administrate::Field::Base
   def lng
     data.last
   end
+
+  def present?
+    lat.present? && lng.present?
+  end
 end

app/views/fields/geopoint_field/_show.html.haml

@@ -1,2 +1,2 @@
-- if field.data.present?
+- if field.present?
   = link_to field.data.join(", "), "https://www.geoportail.gouv.fr/carte?c=#{field.lng},#{field.lat}&z=17&permalink=yes", target: '_blank', rel: 'noopener'