CMake bug prevents successful rebuild

[andrew-wja]

Due to a bug in CMake: https://gitlab.kitware.com/cmake/cmake/-/issues/16528

It is require to force UPDATE_COMMAND /bin/true to bypass a spurious git rebase operation here

caffe/cmake/MKLDNN.cmake

Lines 35 to 37 in 3f494b4

	#--Download step
	GIT_REPOSITORY https://github.com/intel/mkl-dnn.git
	GIT_TAG ${MKLDNN_COMMIT}