message: [docker] do not fail on submodule update failure
  Docker Hub clones repositories with `--recursive`, and since it is using
  a old version of git. The git file is pointing to absolute path. After
  copying into docker, the path is incorrect.
  This commit allows git submodule failure in `script/bootstrap`.
diff: @@ -164,9 +164,10 @@ install_cpputest()
  main()
  {
  . $BEFORE_HOOK
  + # TODO remove `|| true` after docker hub builder gets its git upgraded
  + git submodule update --init --recursive || true
  install_packages
  with RELEASE || install_cpputest
  - git submodule update --init --recursive
  ./bootstrap
  . $AFTER_HOOK
  }
  