Update mobilenet_v3_small-fpn.yaml

Author: Y-T-G

cfg/detect/mobilenet_v3_small-fpn.yaml

@@ -34,4 +34,3 @@ head:
   - [[-1, -11], 1, Concat, [1]]                                                #  (1, 1072, 20, 20) - 15
   - [-1, 2, C3k2, [576, True]]                                                 #  (1, 960, 20, 20) - 16
   - [[-7, -4, -1], 1, Detect, [nc]]                                            #  17
-  - [-1, 1, nn.Identity, []]