Merge #2622

2622: Fix smtplib.LMTP wrong argument name: ip -> host r=mergify[bot] a=zozzz

## What type of PR?

bug-fix

## What does this PR do?

Bug fix when sending welcome message.

### Related issue(s)
- Mention an issue like: -
- Auto close an issue like: closes -

## Prerequisites
Before we can consider review and merge, please make sure the following list is done and checked.
If an entry in not applicable, you can check it or remove it from the list.

- [ ] In case of feature or enhancement: documentation updated accordingly
- [ ] Unless it's docs or a minor change: add [changelog](https://mailu.io/master/contributors/workflow.html#changelog) entry file.


Co-authored-by: Vetési Zoltán <zozzz@trigon.hu>

core/admin/mailu/models.py

@@ -421,7 +421,7 @@ class Email(object):
         """ send an email to the address """
         try:
             f_addr = f'{app.config["POSTMASTER"]}@{idna.encode(app.config["DOMAIN"]).decode("ascii")}'
-            with smtplib.LMTP(ip=app.config['IMAP_ADDRESS'], port=2525) as lmtp:
+            with smtplib.LMTP(host=app.config['IMAP_ADDRESS'], port=2525) as lmtp:
                 to_address = f'{self.localpart}@{idna.encode(self.domain_name).decode("ascii")}'
                 msg = text.MIMEText(body)
                 msg['Subject'] = subject