adding ngx_http_js_module nginx module

[ajcs3]

Can we add ngx_http_js_module to the nginx binary. This module is quite stable and comes handy to extend nginx. Even the official docker images of nginx includes NJS out of the box.

[arjun024]

I don't know much about njs, but I'm not convinced we should be bundling this module up with the default NGINX dependency. Users can include their own modules under the modules dir. See https://docs.cloudfoundry.org/buildpacks/nginx/#-loading-dynamic-modules