fix dssm

dssm/network_conf.py

@@ -151,7 +151,7 @@ class DSSM(object):
         logger.info("create a sequence_conv_pool which context width is 4")
         conv_4 = create_conv(4, self.dnn_dims[1], "cnn")
 
-        return conv_3, conv_4
+        return paddle.layer.concat(input=[conv_3, conv_4])
 
     def create_dnn(self, sent_vec, prefix):
         # if more than three layers, than a fc layer will be added.