lazy-umount-nfs.service: Try normal umount first

When this service is started, automount already attempted to unmount the
nfs mounts it is responsible for. However, we may have other nfs mounts
(e.g. those done manually by a system administrator). If we just
disconnect those, we would shutdown before attempting to write dirty
data back and release delegations and locks on the server.

Try a normal umount before we give up and just disconnect the mounts.

misc_systemd_units/lazy-umount-nfs.service

@@ -7,6 +7,7 @@ DefaultDependencies=false
 [Service]
 Type=oneshot
 RemainAfterExit=yes
+ExecStart=/bin/umount -a -t nfs4
 ExecStart=/bin/umount -a -t nfs4 -l
 
 [Install]