Merge pull request #567 from noesya/fix_permalinks_static_export

fix permalinks static export

app/views/admin/communication/websites/configs/permalinks/static.html.erb

@@ -10,7 +10,8 @@ persons:        <%= @website.special_page(:persons).path_without_language %>:slu
 <% if @website.has_organizations? %>
 organizations:  <%= @website.special_page(:organizations).path_without_language %>:slug/
 <% end %>
-<% if @website.has_authors? %>
+<%# website might have authors but no communication_posts (if a post unpublished exists) %>
+<% if @website.has_authors? && @website.has_communication_posts? %>
 authors:        <%= @website.special_page(:persons).path_without_language %>:slug/<%= @website.special_page(:communication_posts).slug %>/
 <% end %>
 <% if @website.has_education_diplomas? %>