[SPARK-4880] remove spark.locality.wait in Analytics

spark.locality.wait set to 100000 in examples/graphx/Analytics.scala.
Should be left to the user.

Author: Ernest <earneyzxl@gmail.com>

Closes #3730 from Earne/SPARK-4880 and squashes the following commits:

d79ed04 [Ernest] remove spark.locality.wait in Analytics

examples/src/main/scala/org/apache/spark/examples/graphx/Analytics.scala

@@ -46,7 +46,7 @@ object Analytics extends Logging {
     }
     val options = mutable.Map(optionsList: _*)
 
-    val conf = new SparkConf().set("spark.locality.wait", "100000")
+    val conf = new SparkConf()
     GraphXUtils.registerKryoClasses(conf)
 
     val numEPart = options.remove("numEPart").map(_.toInt).getOrElse {