Fix compilation

Author: tdas

external/kafka-0-10-sql/src/test/scala/org/apache/spark/sql/kafka010/KafkaSourceSuite.scala

@@ -38,6 +38,7 @@ import org.apache.spark.sql.ForeachWriter
 import org.apache.spark.sql.execution.streaming._
 import org.apache.spark.sql.functions.{count, window}
 import org.apache.spark.sql.kafka010.KafkaSourceProvider._
+import org.apache.spark.sql.streaming.util.StreamManualClock
 import org.apache.spark.sql.streaming.{ProcessingTime, StreamTest}
 import org.apache.spark.sql.test.{SharedSQLContext, TestSparkSession}
 import org.apache.spark.util.Utils