xfce4-notifyd: fix build for libnotify 0.7.x

the patch included during last commit only made latest xfce4-notifyd work with
old version of libnotify. I expected it to work also for libnotify 0.7.x but
that failed so remove the patch.

Signed-off-by: Andreas Müller <schnitzeltony@googlemail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>