Fix CheckpointSuite.

Author: Marcelo Vanzin

streaming/src/test/scala/org/apache/spark/streaming/CheckpointSuite.scala

@@ -35,6 +35,7 @@ import org.scalatest.concurrent.Eventually._
 import org.scalatest.time.SpanSugar._
 
 import org.apache.spark.{SparkConf, SparkContext, SparkFunSuite, TestUtils}
+import org.apache.spark.internal.config._
 import org.apache.spark.rdd.RDD
 import org.apache.spark.streaming.dstream._
 import org.apache.spark.streaming.scheduler._
@@ -406,7 +407,8 @@ class CheckpointSuite extends TestSuiteBase with DStreamCheckpointTester
     // explicitly.
     ssc = new StreamingContext(null, newCp, null)
     val restoredConf1 = ssc.conf
-    assert(restoredConf1.get("spark.driver.host") === "localhost")
+    val defaultConf = new SparkConf()
+    assert(restoredConf1.get("spark.driver.host") === defaultConf.get(DRIVER_HOST_ADDRESS))
     assert(restoredConf1.get("spark.driver.port") !== "9999")
   }