In (*Server).StartTLS, it's unnecessary to create an http.Client
with a Transport, because a new one will be created with the
TLSClientConfig later.
Change-Id: I086e28717e9739787529006c3f0296c8224cd790
GitHub-Last-Rev:
33724596bd901a05a91654f8c2df233aa6563ea6
GitHub-Pull-Request: golang/go#60124
Reviewed-on: https://go-review.googlesource.com/c/go/+/494355
Run-TryBot: t hepudds <thepudds1460@gmail.com>
Reviewed-by: Heschi Kreinick <heschi@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Damien Neil <dneil@google.com>
Reviewed-by: qiulaidongfeng <2645477756@qq.com>