Revert "Fix clazy warning"

CCMAIL: montel@kde.org

org.kde.pim.mailtransport.smtpplugin: Login started
QObject::connect: Cannot queue arguments of type 'KSmtp::ServerResponse'
(Make sure 'KSmtp::ServerResponse' is registered using qRegisterMetaType().)

This reverts commit 80d61bbda1ac82fb462630e39baa9383fe851aa1.