add no-mailing-list condition

views/DE/project/mailinglists.pug

@@ -20,6 +20,9 @@ html(lang="de")
             div(class="col-md-12 margin_bottom_30")
                 h2(class="text-center color_708090") <strong>Aktive Mailinglisten</strong>
                 div(class="table-responsive table-borderless")
+                    if !mailinglists
+                        p There is no active mailing list at the moment
+                    else
                         table(class="table table-striped table-bordered table-hover")
                             thead()
                                 tr()