internal/worker: don't require https index URLs

Sometimes the golang index has a good reason to have an http address:

- It's running locally on your dev machine.
- It's running in production, but on a network-local address.

This removes the https requirement that we have to patch in at the moment.

Change-Id: Ib6577a63463c5b2e7cc537532a9ca20ac63fd1d4
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/685456
Reviewed-by: Jonathan Amsterdam <[email protected]>
Reviewed-by: Carlos Amedee <[email protected]>
kokoro-CI: kokoro <[email protected]>
LUCI-TryBot-Result: Go LUCI <[email protected]>

Author: jeanbza

internal/index/index.go

@@ -31,17 +31,13 @@ type Client struct {
 }
 
 // New constructs a *Client using the provided rawurl, which is expected to
-// be an absolute URI that can be directly passed to http.Get.
+// be able to be passed to http.Get.
 func New(rawurl string) (_ *Client, err error) {
 	defer derrors.Add(&err, "index.New(%q)", rawurl)
 
-	u, err := url.Parse(rawurl)
-	if err != nil {
+	if _, err := url.Parse(rawurl); err != nil {
 		return nil, fmt.Errorf("url.Parse(%q): %v", rawurl, err)
 	}
-	if u.Scheme != "https" {
-		return nil, fmt.Errorf("scheme must be https (got %s)", u.Scheme)
-	}
 	return &Client{url: strings.TrimRight(rawurl, "/"), httpClient: &http.Client{Transport: &ochttp.Transport{}}}, nil
 }