分片后只能用 http 模式请求，且无法使用 BasicAuth 或者 BearerToken

[HaoKunT]

func (i *Injector) injectJobs(cfg *config.Config) error {
	for _, job := range cfg.ScrapeConfigs {
		if i.option.ProxyURL != "" {
			u, err := url.Parse(i.option.ProxyURL)
			if err != nil {
				return err
			}

			job.HTTPClientConfig.ProxyURL = config_util.URL{
				URL: u,
			}
		}

		job.ServiceDiscoveryConfigs = []discovery.Config{
			discovery.StaticConfig(target2targetGroup(job.JobName, i.curTargets[job.JobName])),
		}

		job.Scheme = "http"
		job.HTTPClientConfig.BearerToken = ""
		job.HTTPClientConfig.BasicAuth = nil
		job.HTTPClientConfig.TLSConfig = config_util.TLSConfig{}

		// fix invalid label
		job.RelabelConfigs = []*relabel.Config{
			{
				Separator:   ";",
				Regex:       relabel.MustNewRegexp(target.PrefixForInvalidLabelName + "(.+)"),
				Replacement: "$1",
				Action:      relabel.LabelMap,
			},
		}
	}

	return nil
}

injectJobs 函数直接硬编码了请求方式，去掉了auth(#9)，猜测是因为sidecar需要代理prometheus的scrape请求，是否有办法将auth加回？