IMPALA-7067: deflake test_cancellation
IMPALA-7067: deflake test_cancellation

Tweak the query so that it still runs for a long time but
can cancel the fragment quicker instead of being
stuck in a long sleep() call.

Change-Id: I0c90d4f5c277f7b0d5561637944b454f7a44c76e
Reviewed-on: http://gerrit.cloudera.org:8080/10499
Reviewed-by: Tim Armstrong <2f8e34250f03a653da3dc27f7ec203eafdde80fc@cloudera.com>
Tested-by: Tim Armstrong <2f8e34250f03a653da3dc27f7ec203eafdde80fc@cloudera.com>

cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala,cloudera/Impala