message: [bootstrap] install dnsutils for reference device
  This commit installs the dnsutils package for reference device.
  The dnsutils package includes tools like dig, which can be used to
  test DNS servers on BR.
diff: @@ -88,7 +88,7 @@ install_packages_apt()
  sudo apt-get install --no-install-recommends -y libjsoncpp1 libjsoncpp-dev
  # reference device
  - without REFERENCE_DEVICE || sudo apt-get install --no-install-recommends -y radvd
  + without REFERENCE_DEVICE || sudo apt-get install --no-install-recommends -y radvd dnsutils
  # backbone-router
  without BACKBONE_ROUTER || sudo apt-get install --no-install-recommends -y iptables libnetfilter-queue1 libnetfilter-queue-dev
  