Update cheatsheet.md

fix CLA sign

content/en/docs/reference/kubectl/cheatsheet.md

@@ -375,7 +375,7 @@ Examples using `-o=custom-columns`:
 # All images running in a cluster
 kubectl get pods -A -o=custom-columns='DATA:spec.containers[*].image'
 
-# All images running in default namespace, grouped by Pod
+# All images running in namespace: default, grouped by Pod
 kubectl get pods --namespace default --output=custom-columns="NAME:.metadata.name,IMAGE:.spec.containers[*].image"
 
  # All images excluding "k8s.gcr.io/coredns:1.6.2"