Fix main class name in Dockerfile

Author: szarnyasg

Dockerfile

@@ -18,7 +18,7 @@ ENV DRIVER_MEMORY "5G"
 # the SPARK_* variables are used by submit.sh to configure the Spark job
 ENV SPARK_LOCAL_DIRS ${TEMP_DIR}
 ENV SPARK_SUBMIT_ARGS --executor-memory ${EXECUTOR_MEMORY} --driver-memory ${DRIVER_MEMORY}
-ENV SPARK_APPLICATION_MAIN_CLASS ldbc.snb.datagen.spark.LdbcDatagen
+ENV SPARK_APPLICATION_MAIN_CLASS ldbc.snb.datagen.LdbcDatagen
 ENV SPARK_MASTER_URL local[*]
 ENV SPARK_APPLICATION_JAR_LOCATION /mnt/datagen.jar