Update app.py

app.py

@@ -219,7 +219,7 @@ def detect_face(img):
         human_face = [idx for idx, val in enumerate(detections) if val[0] == 'Person']
     
         if len(human_face) == 0:
-            return None
+            return []
         else:
             # Only get human face detections
             faces = detect_person_face(img, [detections[idx] for idx in human_face])