fix normal.npy file save mistake

app.py

@@ -116,7 +116,7 @@ def predict_depth_normal(img, model_selection="vit-small", fx=1000.0, fy=1000.0,
     depth_file = f"{state_cache['save_dir']}/depth.npy"
     normal_file = f"{state_cache['save_dir']}/normal.npy"
     np.save(depth_file, pred_depth)
-    np.save(normal_file, pred_depth)
+    np.save(normal_file, pred_normal)
 
     ##formatted = (output * 255 / np.max(output)).astype('uint8')
     img = Image.fromarray(pred_color)