net: delete TestDialTimeoutHandleLeak
net: delete TestDialTimeoutHandleLeak

It is too flaky. Tried to make it more reliable,
but that affects other tests (they run too long),
because we do unusual things here, like attempting
to connect to non-existing address and interrupt.

R=golang-dev, bradfitz, mikioh.mikioh
CC=golang-dev
https://codereview.appspot.com/7314097

wesolows/golang,wesolows/golang-old,wesolows/golang-old,wesolows/golang,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,firebitsbr/golang-old,wesolows/golang,wesolows/golang,wesolows/golang-old,wesolows/golang-old,wesolows/golang,firebitsbr/golang-old,wesolows/golang-old,firebitsbr/golang-old,wesolows/golang,firebitsbr/golang-old,firebitsbr/golang-old,wesolows/golang-old