Update delete-by-query.asciidoc
Tried my best to clarify sentence on `_delete_by_query` docs.
@@ -384,7 +384,8 @@ POST _tasks/r1A2WoRbTwKZ516z6NEs5A:36619/_cancel
The task ID can be found using the <<tasks,tasks API>>.
Cancellation should happen quickly but might take a few seconds. The task status
-API above will continue to list the task until it is wakes to cancel itself.
+API above will continue to list the delete by query task until this task checks that it
+has been cancelled and terminates itself.
[float]
