Log Message:
Update to 3.9. From the changelog:

* Catch and error out if a user adds a feed with a duplicate name.
* Split sender into both sendmail's -F and -f.
* Fix an error with SMTPConnectionError inhertence order ("does not
  take keyword arguments").
* Add a new `smtp-ssl-protocol` setting, to select acceptable
  protocols for SMTP connections.
* Fix non-compliant User-Agent header for HTTP/1.1.
* Fix an error in the NoToEmailAddress invocation.
* Add a new `trust-link` setting, to prefer the `link` attribute
  over the `id` attribute for identifying entries.