Fix bundling of dashboard in binary packages. (netdata#8844)

This removes some code from the dashboard bundling script that was left
over from before we changed how we were handling prefixing the old
dashboard. The script did not get properly tested after that change in
design, so the code unfortunately made it into master and broke package
builds.

packaging/bundle-dashboard.sh

@@ -12,7 +12,3 @@ sha256sum -c "${SRCDIR}/packaging/dashboard.checksums" || exit 1
 tar -xzf "${DASHBOARD_TARBALL}" -C "${SRCDIR}/tmp" || exit 1
 # shellcheck disable=SC2046
 cp -a $(find "${SRCDIR}/tmp" -mindepth 1 -maxdepth 1) "${WEBDIR}"
-cp -a "${WEBDIR}/old/dashboard_info.js" "${WEBDIR}"
-cp -a "${WEBDIR}/old/dashboard.slate.css" "${WEBDIR}"
-cp -a "${WEBDIR}/old/dashboard.css" "${WEBDIR}"
-cp -a "${WEBDIR}/old/main.css" "${WEBDIR}"