windows/linux path hack fix

app.py

@@ -2,6 +2,9 @@ import gradio as gr
 from nbconvert import export
 import numpy as np
 from fastai.vision.all import *
+import pathlib
+plt = platform.system()
+if plt == 'Linux': pathlib.WindowsPath = pathlib.PosixPath
 
 learner = load_learner("model.pkl")
 categories = ('happy', 'upset')