Fix host redirect handling

If you try to clone from a url that redirects to another host
e.g. `example.com/repo` -> `github.com/org/repo.git`,
it results in a redirect to `example.com/org/repo.git`
because ModifyEndpointIfRedirect only takes into account the scheme and path.

Signed-off-by: DisposaBoy <disposaboy@kuroku.io>

plumbing/transport/http/common.go

@@ -151,7 +151,14 @@ func (s *session) ModifyEndpointIfRedirect(res *http.Response) {
 		return
 	}
 
+	host, port, err := net.SplitHostPort(r.URL.Host)
+	if err != nil {
+		host = r.URL.Host
+	}
+
 	s.endpoint.Protocol = r.URL.Scheme
+	s.endpoint.Host = host
+	s.endpoint.Port, _ = strconv.Atoi(port)
 	s.endpoint.Path = r.URL.Path[:len(r.URL.Path)-len(infoRefsPath)]
 }