[CDH4] IMPALA-838: Fix premature timeout of sessions (missing diff)

Restores two lines of diff which were missing from the committed version
of this patch (082f332).

Change-Id: Iea3867ceffa88dfe82a07e0b0ad1d83276806005
Reviewed-on: http://gerrit.ent.cloudera.com:8080/1937
Reviewed-by: Henry Robinson <henry@cloudera.com>
Tested-by: Henry Robinson <henry@cloudera.com>