Fix style

Author: Andrew Or

core/src/main/scala/org/apache/spark/deploy/rest/SubmitRestProtocolException.scala

@@ -33,4 +33,4 @@ private[spark] class SubmitRestMissingFieldException(message: String)
  * An exception thrown if the REST client cannot reach the REST server.
  */
 private[spark] class SubmitRestConnectionException(message: String, cause: Throwable)
-  extends SubmitRestProtocolException(message, cause)
+  extends SubmitRestProtocolException(message, cause)