net/http: simplify Conn lifetimes in TestClientTimeoutKillsConn tests
This is intended to fix the failure mode observed in
https://build.golang.org/log/
f153e06ed547517fb2cddb0fa817fea40a6146f7,
but I haven't been able to reproduce that failure mode locally so I'm
not sure whether it actually does.
Change-Id: Ib14378f1299a76b54013419bdc715a9dbdd94667
Reviewed-on: https://go-review.googlesource.com/c/go/+/478235
Auto-Submit: Bryan Mills <bcmills@google.com>
Reviewed-by: Damien Neil <dneil@google.com>
Run-TryBot: Bryan Mills <bcmills@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>