sudoers: Fix of typo ovirt-shutdown-wrapper{s,}

Change-Id: I9247c6c2048a1f20f048c8232d2c18698a414073
Bug-Url: https://bugzilla.redhat.com/1155921
Signed-off-by: Vinzenz Feenstra <vfeenstr@redhat.com>
(cherry picked from commit e0e6e452f29730ea8c4a2dc889787e09e71c6bc7)