fix: remove redundant line in retry-handler (#4554)

Author: Uzlopak

lib/handler/retry-handler.js

@@ -92,8 +92,6 @@ class RetryHandler {
 
     function shouldRetry (passedErr) {
       if (passedErr) {
-        this.headersSent = true
-
         this.headersSent = true
         this.handler.onResponseStart?.(controller, statusCode, headers, statusMessage)
         controller.resume()