Ensure that notification user does not already exist

src/freedombone-notification

@@ -83,9 +83,10 @@ fi
 
 if [ -d /etc/prosody ]; then
     notification_user_password=$(openssl rand -base64 32 | tr -dc A-Za-z0-9 | head -c 30 ; echo -n '')
+    prosodyctl deluser "notification@$HOSTNAME" 2> /dev/null
     if prosodyctl register "notification" "$HOSTNAME" "$notification_user_password" 2> /dev/null; then
         curl http://localhost:5280/msg/user -u "notification@$HOSTNAME:$notification_user_password" -H "Content-Type: text/plain" -d "$MESSAGE" 2> /dev/null
-        prosodyctl deluser "notification@$HOSTNAME" 2> /dev/nul
+        prosodyctl deluser "notification@$HOSTNAME" 2> /dev/null
     fi
 fi