fix kornia batch problem

app.py

@@ -123,7 +123,7 @@ def kornia_detect(img, confidence_threshold, nms_threshold):
 
     with torch.no_grad():
         dets = face_detection(img)
-    dets = [FaceDetectorResult(o) for o in dets]
+    dets = [FaceDetectorResult(o) for o in dets[0]]
 
     # show image