message: Force old configuration when installing packages for release
  When building a release on the 32 bits Ubuntu 14.04, the automated
  install runs into a prompt to choose an option with regard to
  /etc/protocols being modified earlier.
diff: @@ -74,7 +74,10 @@ if "$additional_dev_packages"; then
  $(first_available_package php-mbstring libapache2-mod-php5))
  fi
  -apt-get -y install "${binary_packages[@]}"
  +# The 32 bits ubuntu 14.04 image has /etc/protocols modified which
  +# will cause a prompt here. Force retaining the old configuration here.
  +apt-get -y -o Dpkg::Options::="--force-confdef" \
  + -o Dpkg::Options::="--force-confold" install "${binary_packages[@]}"
  # src_packages might be empty. The below placates set -u, see:
  # http://stackoverflow.com/questions/7577052/bash-empty-array-expansion-with-set-u
  