Restore SCRAPE_URI env var

This was removed in #420 by mistake

exporter.go

@@ -85,7 +85,7 @@ var (
 	webConfig     = kingpinflag.AddFlags(kingpin.CommandLine, ":9113")
 	metricsPath   = kingpin.Flag("web.telemetry-path", "Path under which to expose metrics.").Default("/metrics").Envar("TELEMETRY_PATH").String()
 	nginxPlus     = kingpin.Flag("nginx.plus", "Start the exporter for NGINX Plus. By default, the exporter is started for NGINX.").Default("false").Envar("NGINX_PLUS").Bool()
-	scrapeURIs    = kingpin.Flag("nginx.scrape-uri", "A URI or unix domain socket path for scraping NGINX or NGINX Plus metrics. For NGINX, the stub_status page must be available through the URI. For NGINX Plus -- the API. Repeatable for multiple URIs.").Default("http://127.0.0.1:8080/stub_status").HintOptions("http://127.0.0.1:8080/stub_status", "http://127.0.0.1:8080/api").Strings()
+	scrapeURIs    = kingpin.Flag("nginx.scrape-uri", "A URI or unix domain socket path for scraping NGINX or NGINX Plus metrics. For NGINX, the stub_status page must be available through the URI. For NGINX Plus -- the API. Repeatable for multiple URIs.").Default("http://127.0.0.1:8080/stub_status").Envar("SCRAPE_URI").HintOptions("http://127.0.0.1:8080/stub_status", "http://127.0.0.1:8080/api").Strings()
 	sslVerify     = kingpin.Flag("nginx.ssl-verify", "Perform SSL certificate verification.").Default("false").Envar("SSL_VERIFY").Bool()
 	sslCaCert     = kingpin.Flag("nginx.ssl-ca-cert", "Path to the PEM encoded CA certificate file used to validate the servers SSL certificate.").Default("").Envar("SSL_CA_CERT").String()
 	sslClientCert = kingpin.Flag("nginx.ssl-client-cert", "Path to the PEM encoded client certificate file to use when connecting to the server.").Default("").Envar("SSL_CLIENT_CERT").String()