small fix

app.py

@@ -25,7 +25,7 @@ def load_data():
         df.to_pickle("df_dashboard.pkl") # TODO
     except Exception as e:
         warn("Could not load data from feature store (most likely due to Port issues with Hopsworks). Trying to load same data that is stored with the model. Full exception:")
-        warn(e)
+        warn(str(e))
 
     # Load model including the generated images and evaluation scores
     mr = project.get_model_registry()