update BN layer
update BN layer

Signed-off-by: YAO Matrix <4f2f5096877db473be5be541cbdfd0a6eed685a2@126.com>

yao-matrix/py-R-FCN-MKL,yao-matrix/py-R-FCN-MKL,yao-matrix/py-R-FCN-MKL,yao-matrix/py-R-FCN-MKL,yao-matrix/py-R-FCN-MKL