rephrase more naturally

includes/helper/email_helper.php

@@ -20,7 +20,7 @@ function engelsystem_email_to_user($recipient_user, $title, $message, $not_if_it
     $message = sprintf(_('Hi %s,'), $recipient_user['Nick']) . "\n\n"
         . _('here is a message for you from the engelsystem:') . "\n\n"
         . $message . "\n\n"
-        . _('This email is autogenerated and has not to be signed. You got this email because you are registered in the engelsystem.');
+        . _('This email is autogenerated and has not been signed. You got this email because you are registered in the engelsystem.');
 
     gettext_locale();
 

locale/de_DE.UTF-8/LC_MESSAGES/default.po

@@ -641,7 +641,7 @@ msgstr "hier ist eine Nachricht aus dem Engelsystem für Dich:"
 
 #: /Users/msquare/workspace/projects/engelsystem/includes/helper/email_helper.php:23
 msgid ""
-"This email is autogenerated and has not to be signed. You got this email "
+"This email is autogenerated and has not been signed. You got this email "
 "because you are registered in the engelsystem."
 msgstr ""
 "Diese E-Mail wurde automatisch generiert und muss daher nicht unterschrieben "

locale/pt_BR.UTF.8/LC_MESSAGES/pt_BR.po

@@ -565,7 +565,7 @@ msgstr "aqui está uma mensagem do engelsystem para você:"
 
 #: includes/helper/email_helper.php:12
 msgid ""
-"This email is autogenerated and has not to be signed. You got this email "
+"This email is autogenerated and has not been signed. You got this email "
 "because you are registered in the engelsystem."
 msgstr "Você recebeu esse email porque está registrado no engelsystem."