Package js_program lacks field package-dune-stanzas

[lefessan]

The beginning of the file should be:

(executable
  (name !{library-name})
  (libraries !{dune-libraries} !(package-dune-libraries))
  (modes js)
  !{dune-stanzas}
  !(package-dune-stanzas)
  )

as in https://github.com/OCamlPro/superbol-studio-oss/blob/master/src/vscode/superbol-vscode-platform/dune.drom-tpl