Before this commit `node --debug-port=1234 debug t.js` ignored the
--debug-port= argument, binding to the default port 5858 instead,
making it impossible to debug more than one process on the same
machine that way.
This commit also reduces the number of places where the default port
is hard-coded by one.
Fixes: https://github.com/nodejs/node/issues/3345
PR-URL: https://github.com/nodejs/node/pull/3470
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Fedor Indutny <fedor.indutny@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
