Update quick-reference.md

Correct remove annotation command

Author: py-craft

content/en/docs/reference/kubectl/quick-reference.md

@@ -287,7 +287,7 @@ kubectl label pods my-pod new-label=awesome                      # Add a Label
 kubectl label pods my-pod new-label-                             # Remove a label
 kubectl label pods my-pod new-label=new-value --overwrite        # Overwrite an existing value
 kubectl annotate pods my-pod icon-url=http://goo.gl/XXBTWq       # Add an annotation
-kubectl annotate pods my-pod icon-                               # Remove annotation
+kubectl annotate pods my-pod icon-url-                           # Remove annotation
 kubectl autoscale deployment foo --min=2 --max=10                # Auto scale a deployment "foo"
 ```