nginx 1.19.0 主线版已发布，更新内容如下（貌似就是1.18版本改了个版本号。。。）：
Feature: 使用 OCSP 进行客户端证书验证 Bugfix: 修复与 gRPC 后端搭配使用时，可能出现的"upstream sent frame for closed stream"错误 Bugfix: 如果没有指定"resolver"指令，OCSP stapling 可能无法运行 Bugfix: HTTP/2 连接前言(preface)不正确的链接无法被记录
Changes with nginx 1.19.0 26 May 2020 *) Feature: client certificate validation with OCSP. *) Bugfix: "upstream sent frame for closed stream" errors might occur when working with gRPC backends. *) Bugfix: OCSP stapling might not work if the "resolver" directive was not specified. *) Bugfix: connections with incorrect HTTP/2 preface were not logged.