net/http: skip redirecting in ServeMux when URL path for CONNECT is empty
In 1.21 ServeMux, we had a special-case to skip redirection when a given
path is empty for CONNECT requests:
https://go.googlesource.com/go/+/refs/tags/go1.24.4/src/net/http/servemux121.go#205.
This special case seems to not have been carried over to 1.22 ServeMux.
This causes needless redirection, which this CL fixes.
Fixes #74422
Change-Id: I3cc5b4d195ab0591a9139225b632cbe17f4290db
Reviewed-on: https://go-review.googlesource.com/c/go/+/699915 Reviewed-by: Sean Liao <sean@liao.dev>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Sean Liao <sean@liao.dev> Reviewed-by: Damien Neil <dneil@google.com>