update docs

docs/cn/bvar.md

@@ -92,4 +92,4 @@ process_username : "gejun"
 
 # bvar导出到其它监控系统格式
 
-bvar已支持的其它监控系统格式有[Prometheus](https://prometheus.io)。将Prometheus的抓取url地址的路径设置为`/brpc_prometheus_metrics`即可，例如brpc server跑在本机的8080端口，则抓取url配置为`127.0.0.1:8080/brpc_prometheus_metrics`。
+bvar已支持的其它监控系统格式有[Prometheus](https://prometheus.io)。将Prometheus的抓取url地址的路径设置为`/brpc_metrics`即可，例如brpc server跑在本机的8080端口，则抓取url配置为`127.0.0.1:8080/brpc_metrics`。

docs/en/bvar.md

@@ -92,4 +92,4 @@ The monitoring system should combine data on every single machine periodically a
 
 # Dump to the format of other monitoring system
 
-Currently monitoring system supported by bvar is [Prometheus](https://prometheus.io). All you need to do is to set the path in scraping target url to `/brpc_prometheus_metrics`. For example, if brpc server is running on localhost:8080, the scraping target should be `127.0.0.1:8080/brpc_prometheus_metrics`.
+Currently monitoring system supported by bvar is [Prometheus](https://prometheus.io). All you need to do is to set the path in scraping target url to `/brpc_metrics`. For example, if brpc server is running on localhost:8080, the scraping target should be `127.0.0.1:8080/brpc_metrics`.