node 12+: generates deprecation warning on `OutgoingMessage.prototype._headers`

`require('http').OutgoingMessage.prototype._headers` triggers the warning in node 12+.

I'm using node-recorder in a spawned process using node-preload to include it, and capturing the stdout/stderr output - and by virtue of something in node-recorder's dep tree, this warning is popping up :-.

While the problem isn't in this library, it'd be great if you could either replace the dep responsible, or point me at the proper repo to file an issue on :-) Thanks!