[SPARK-23275][SQL] fix the thread leaking in hive/tests

## What changes were proposed in this pull request?

This is a follow up of apache#20441.

The two lines actually can trigger the hive metastore bug: https://issues.apache.org/jira/browse/HIVE-16844

The two configs are not in the default `ObjectStore` properties, so any run hive commands after these two lines will set the `propsChanged` flag in the `ObjectStore.setConf` and then cause thread leaks.

I don't think the two lines are very useful. They can be removed safely.

## How was this patch tested?

(Please explain how this patch was tested. E.g. unit tests, integration tests, manual tests)
(If this patch involves UI changes, please attach a screenshot; otherwise, remove this)

Please review http://spark.apache.org/contributing.html before opening a pull request.

Author: Feng Liu <[email protected]>

Closes apache#20562 from liufengdb/fix-omm.

sql/hive/src/main/scala/org/apache/spark/sql/hive/test/TestHive.scala

@@ -530,8 +530,6 @@ private[hive] class TestHiveSparkSession(
       // For some reason, RESET does not reset the following variables...
       // https://issues.apache.org/jira/browse/HIVE-9004
       metadataHive.runSqlHive("set hive.table.parameters.default=")
-      metadataHive.runSqlHive("set datanucleus.cache.collections=true")
-      metadataHive.runSqlHive("set datanucleus.cache.collections.lazy=true")
       // Lots of tests fail if we do not change the partition whitelist from the default.
       metadataHive.runSqlHive("set hive.metastore.partition.name.whitelist.pattern=.*")