notify/email.go: fixup smtp.NewClient second param

[ttys3]

1. second param is wrong

2. most time it does not effact the result, but when you are connecting to a localhost smtp server with
   PLAIN AUTH enabled but without TLS enabled. it will fail

I also marked this problem in my smtp-brd FAQ

smtp.plainAuth failed: unencrypted connection
You need either to setup TLS on your SMTP server,
use localhost as a relay or disable authentication.
the answer come from
this issue

The error is because the Go SMTP package doesn't allow authentication without encryption.
From <https://godoc.org/net/smtp#PlainAuth>

PlainAuth will only send the credentials if the connection is using TLS
or is connected to localhost. Otherwise authentication
will fail with an error, without sending the credentials.

the important part is localhost, if your send it localhost:25 or other addr with port, it will fail.

[paskal]

Looks legit. Thank you for the fix!