Revert "systemvm: document workaround for older ACS env with systemvms"

This reverts commit b86b9207bc52514df472f6458d79ea5421a312fb.
diff --git a/source/upgrading/upgrade/_sysvm_restart.rst b/source/upgrading/upgrade/_sysvm_restart.rst
index 93bd622..8f01fb2 100644
--- a/source/upgrading/upgrade/_sysvm_restart.rst
+++ b/source/upgrading/upgrade/_sysvm_restart.rst
@@ -26,22 +26,6 @@
    or do it by using third-party tools such as Ansible.
    Below we are giving instructions for using the "cloudstack-sysvmadm" script.
 
-Note: When upgrading from older CloudStack environments (for example, 4.9-4.13)
-with XenServer or XCP-ng hosts, some systemvms and virtual routers may not have
-ejected or removed the older systemvm.iso. The old systemvm.iso needs to be
-ejected and removed before new systemvms and virtual routers are (re-)created).
-This issue has been fixed in CloudStack 4.15, older enviroments may need the
-following to be run on the XenServer or XCP-ng pool master:
-
-.. parsed-literal::
-
-   # for vm in $(xe vm-list | grep name-label | sed 's/.*name-label.*: //g'); do
-       if [[ $vm == [rvs]-* ]]; then
-         echo "Attempting systemvm.iso eject and remove for $vm";
-         xe vm-cd-eject vm=$vm;
-         xe vm-cd-remove vm=$vm cd-name=systemvm.iso;
-       fi;
-     done
 
 Ensure that the admin port is set to
 8096 by using the "integration.api.port" global parameter. This port