Remove invalid default from address (and name)! Fixes PHPMailer#2396

Changelog

PHPMailer 6.4.1

PHPMailer 6.4.0

PHPMailer 6.3.0

PHPMailer 6.2.0

PHPMailer 6.1.8

PHPMailer 6.1.7

PHPMailer 6.1.6

PHPMailer 5.2.28