update relx-dev.config vm.args copy

[tsloughter]

Recent relx changed the output structure to be releases/ instead of releases/- in order to work with release_handler. Here I've made the change to relx.config overlay for that.

You could also use

{vm_args, "rel/vm.args"}.

Instead, like you do for sys.config.

[jlouis]

This is a dupe, right?

[tsloughter]

No, one was relx.config and this one is relx-dev.config. I was just copying the commit message over and over to different repos, so it looks like a dupe :)

[jlouis]

hah, merged :)