Support opt-out the automatically added trailing slash for publicPath

Is your feature request related to a problem? Please describe. I want to set my publicPath to something like <!--# echo var='public_path' default='' -->, which is a nginx ssi expression.

I have a config like:

new HtmlWebpackPlugin({
  filename: "index.html",
  publicPath: "<!--# echo var='public_path' default='' -->",
}),

I want the output html to be like:

<script src="<!--# echo var='core_root' default='' -->main.js"></script>

But it automatically added a trailing slash for the publicPath, it output:

<script src="<!--# echo var='core_root' default='' -->/main.js"></script>
                                                      ^

Describe the solution you'd like

It would be nice to have an option to opt-out the automatically added trailing slash for publicPath.

Something like:

new HtmlWebpackPlugin({
  filename: "index.html",
  publicPath: "<!--# echo var='public_path' default='' -->",
  publicPathTrailingSlash: false,
}),

P.S. I am using webpack v4 along with html-webpack-plugin v4, so supports it in v4 would be nice, thank you.