go version and deps update, fixed middlewares and metrics

- fixed "API JWT secret empty" warning output format
- fixed metrics initialized when it should not
- fixed middlewares.modifyRequest Host header not working properly

cmd/main.go

@@ -110,6 +110,10 @@ func main() {
 		return
 	}
 
+	if common.APIJWTSecret == nil {
+		logging.Warn().Msg("API JWT secret is empty, authentication is disabled")
+	}
+
 	cfg.StartProxyProviders()
 	config.WatchChanges()