reduce data_layer size of unit test to avoid cuda out of memory on MAC OS

paddle/gserver/tests/concat_table_a.conf

@@ -16,9 +16,9 @@
 
 from paddle.trainer_config_helpers import *
 
-settings(batch_size=1000)
+settings(batch_size=300)
 
-data = data_layer(name ="input", size=100000)
+data = data_layer(name ="input", size=10000)
 
 # emb1 is equal to emb2, note that bias_attr=false 
 # and act=LinearActivation() in default.