only send email when a note actually has content

hedgedoc-expire.py

@@ -215,6 +215,8 @@ class HedgedocExpire:
         with db.prepare('DELETE FROM "Notes" WHERE "id" = $1') as delete_statement:
             for note in self.notes_to_be_expired(db):
                 try:
+
+                    if len(note["content"]) > 0:
                         note_age = datetime.now(timezone.utc) - datetime.fromisoformat(note['updatedAt'])
                         msg = MIMEMultipart()
                         msg['From'] = self.email_sender.mail_from