Fix mail module for python 3.7.0 (#44550) (#44552)

In python 3.7.0, changes in `ssl.py` breaks `smtplib.SMTP_SSL`, which
then breaks `mail` module in ansible.

Run this line in python shell:

    import smtplib;smtplib.SMTP_SSL().connect(host='smtp.gmail.com', port=465)

Before python 3.7.0, we will get:

    (220, b'smtp.gmail.com ESMTP j13-v6sm3086685pgq.56 - gsmtp')

In python 3.7.0, we get such error at `lib/python3.7/ssl.py` line 843, method `_create`:

    ValueError: server_hostname cannot be an empty string or start with a leading dot.

The ssl module is using host info on SMTP_SSL instance, which is not set.
The fix/workaround is simple, just pass host info to it:

    import smtplib;smtplib.SMTP_SSL(host='smtp.gmail.com').connect(host='smtp.gmail.com', port=465)

Fixes: #44550

Signed-off-by: Guo Qiao <guoqiao@gmail.com>

changelogs/fragments/44552-mail-py370-compat.yml

@@ -0,0 +1,2 @@
+bugfixes:
+- fix mail module for python 3.7.0 (https://github.com/ansible/ansible/pull/44552)

lib/ansible/modules/notification/mail.py

@@ -248,7 +248,7 @@ def main():
     try:
         if secure != 'never':
             try:
-                smtp = smtplib.SMTP_SSL(timeout=timeout)
+                smtp = smtplib.SMTP_SSL(host=host, timeout=timeout)
                 code, smtpmessage = smtp.connect(host, port=port)
                 secure_state = True
             except ssl.SSLError as e: