Remove unneeded nuke cmd

docs/troubleshooting.rst

@@ -413,6 +413,5 @@ OAS installation in order to start from scratch:
 
     cluster$ /usr/local/bin/k3s-killall.sh
     cluster$ systemctl disable k3s
-    cluster$ mount | egrep '(kubelet|nsfs|k3s)' | cut -d' ' -f 3 | xargs --no-run-if-empty -n 1 umount
     cluster$ rm -rf /var/lib/{rancher,OpenAppStack,kubelet,cni,docker,etcd} /etc/{kubernetes,rancher} /var/log/{OpenAppStack,containers,pods} /tmp/k3s /etc/systemd/system/k3s.service
     cluster$ systemctl reboot