Update stafnet_dataset.py

Author: dylan-yin

ppsci/data/dataset/stafnet_dataset.py

@@ -6,9 +6,8 @@
 import pandas
 try:
     import pgl
-except ModuleNotFoundError as e:
-    logger.error("please install pgl with \'pip install pgl\'.") 
-    raise ModuleNotFoundError(str(e))
+except ModuleNotFoundError:
+    pass
 from paddle import io
 from paddle.io import DataLoader
 from scipy.spatial.distance import cdist