fix(scf): always flush the writer.

server/scf.go

@@ -116,23 +116,20 @@ func RunLambdaClient(bot *coolq.CQBot, conf *config.LambdaServer) {
 
 	for {
 		req := cli.next()
-		if req == nil {
-			writer := lambdaResponseWriter{statusCode: 200}
-			_, _ = writer.Write(nil)
-			continue
-		}
+		writer := lambdaResponseWriter{statusCode: 200, header: make(http.Header)}
 		func() {
 			defer func() {
 				if e := recover(); e != nil {
 					log.Warnf("Lambda 出现不可恢复错误: %v\n%s", e, debug.Stack())
 				}
 			}()
-			writer := lambdaResponseWriter{header: make(http.Header)}
+			if req != nil {
 				server.ServeHTTP(&writer, req)
+			}
+		}()
 		if err := writer.flush(); err != nil {
 			log.Warnf("Lambda 发送响应失败: %v", err)
 		}
-		}()
 	}
 }