Revert "src: fix stuck debugger process"

This reverts commit ff877e93.

Reverted for breaking `node --debug-brk -e 0`.  It should immediately
quit but instead it hangs now.

PR-URL: https://github.com/nodejs/node/pull/3585


Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: James M Snell <jasnell@gmail.com>