Update clusterversion.md

Update oc get clusterversion command.

Author: theodor2311

docs/dev/clusterversion.md

@@ -8,7 +8,7 @@ This object is used by the administrator to declare their target cluster state,
 You can extract the current update image from the `ClusterVersion` object:
 
 ```console
-$ oc get clusterversion -o jsonpath='{.status.current.image}{"\n"}' version
+$ oc get clusterversion -o jsonpath='{.status.desired.image}{"\n"}' version
 registry.svc.ci.openshift.org/openshift/origin-release@sha256:c1f11884c72458ffe91708a4f85283d591b42483c2325c3d379c3d32c6ac6833
 ```