Commit ce7ae55e introduced a typo in virtlockd-admin socket file

/usr/lib/systemd/system/virtlockd-admin.socket:7: Unknown lvalue
'Server' in section 'Socket'

Change 'Server' to 'Service'.
Signed-off-by: NJim Fehlig <jfehlig@suse.com>
Reviewed-by: NErik Skultety <eskultet@redhat.com>