Move a bracket in validateSettings of SparkConf

Move a bracket in validateSettings of SparkConf

Author: hzw19900416 <carlmartinmax@gmail.com>

Closes #2012 from hzw19900416/codereading and squashes the following commits:

e717fb6 [hzw19900416] Move a bracket in validateSettings of SparkConf

(cherry picked from commit 76eaeb4523ee01cabbea2d867daac48a277885a1)
Signed-off-by: Josh Rosen <joshrosen@apache.org>