net: wrap connect in nextTick

Fixes an edge case regression introduced in
1bef7174.

With the lookup being skipped, an error could be emitted before an
error listener has been added.

An example of this was presented by changing the server’s IP address
and then immediately making a request to the old address.

Related: https://github.com/nodejs/io.js/pull/1823
PR-URL: https://github.com/nodejs/io.js/pull/2054


Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-by: Trevor Norris <trev.norris@gmail.com>