message: remove the py3 flag in mkl contianer build
diff: @@ -301,8 +301,6 @@ do
  if [[ "${PYTHON}" == "python3" ]]; then
  TF_DOCKER_BUILD_ARGS+=("--build-arg WHL_DIR=/tmp/pip3")
  TF_DOCKER_BUILD_ARGS+=("--build-arg PIP=pip3")
  - FINAL_TAG="${FINAL_TAG}-py3"
  - ROOT_CONTAINER_TAG="${ROOT_CONTAINER_TAG}-py3"
  fi
  TF_DOCKER_BUILD_ARGS+=("--build-arg PYTHON=${PYTHON}")
  