[SPARK-2986] [SQL] fixed: setting properties does not effect

it seems that set command does not run by SparkSQLDriver. it runs on hive api.
user can not change reduce number by setting spark.sql.shuffle.partitions

but i think setting hive properties seems just a role to spark sql.

Author: guowei <guowei@upyoo.com>

Closes #1904 from guowei2/temp-branch and squashes the following commits:

7d47dde [guowei] fixed: setting properties like spark.sql.shuffle.partitions does not effective

(cherry picked from commit 63d6777737ca8559d4344d1661500b8ad868bb47)
Signed-off-by: Michael Armbrust <michael@databricks.com>