Address the comments

Author: jerryshao

streaming/src/main/scala/org/apache/spark/streaming/Checkpoint.scala

@@ -48,11 +48,11 @@ class Checkpoint(@transient ssc: StreamingContext, val checkpointTime: Time)
     // Reload properties for the checkpoint application since user wants to set a reload property
     // or spark had changed its value and user wants to set it back.
     val propertiesToReload = List(
+      "spark.driver.host",
+      "spark.driver.port",
       "spark.master",
       "spark.yarn.keytab",
-      "spark.yarn.principal",
-      "spark.driver.host",
-      "spark.driver.port")
+      "spark.yarn.principal")
 
     val newSparkConf = new SparkConf(loadDefaults = false).setAll(sparkConfPairs)
       .remove("spark.driver.host")