fix python style

Author: mengxr

python/pyspark/mllib/recommendation.py

@@ -65,13 +65,13 @@ class ALS(object):
     SPARK-3990: In Spark 1.1.x, we use Kryo serialization by default in
     PySpark. ALS does not work under this default setting. You can switch
     back to the default Java serialization by setting:
-    
+
     spark.serializer=org.apache.spark.serializer.JavaSerializer
 
     Please go to http://spark.apache.org/docs/latest/configuration.html
     for instructions on how to configure Spark.
     """
-    
+
     @classmethod
     def train(cls, ratings, rank, iterations=5, lambda_=0.01, blocks=-1):
         sc = ratings.context