[DOCS] Minor editorial change
[DOCS] Minor editorial change

Turn "royal we" into imperative statement.

Change-Id: Ib78e851761796a1751e6adaaffa049b1fbb58b88
Reviewed-on: http://gerrit.cloudera.org:8080/9064
Reviewed-by: Alex Rodoni <b46da68bf9b818cec7052f7cdfe9b3e69485676b@cloudera.com>
Reviewed-by: John Russell <308573a947c636ab812b35943b6242633bef8113@cloudera.com>
Tested-by: Impala Public Jenkins

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