Remove triggers needed to upgrade from legacy GRUB
    
    The legacy GRUB package (grub2 < 1.99-4) had a %preun scriptlet that did a
    rm -f /boot/%{name}/*.{mod,img,lst} and caused users who upgraded to grub2
    to have an empty /boot/%{name} directory, leading to an unbootable system.
    
    To workaround this, a set of %triggerun and %triggerpostun triggers were
    added that backup and restore the /boot/%{name} directory. But that was an
    issue in Fedora 16, almost a decade ago. These aren't needed anymore.
    
    Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>