translated subscject text of confirmation mail

src/main/java/de/srsoftware/widerhall/data/MailingList.java

@@ -645,7 +645,7 @@ public class MailingList implements MessageHandler, ProblemListener {
         try {
             var config = Configuration.instance();
             var url = new StringBuilder(config.baseUrl()).append("/web/confirm?token=").append(member.token()).toString();
-            var subject = t("[{}] Please confirm your list subscription",name());
+            var subject = t("[{}] Bitte bestätigen Sie Ihr Listen-Abonnement",name());
             var text = template.add(URL,url).add(LIST_NAME,name()).render();
             smtp.send(email(),name(),user.email(),subject,text);
         } catch (UnsupportedEncodingException e) {