fix: start supporting response.writableEnded in transaction's context. (#3430)

* fix: Start supporting response.writableEnded in transaction's context.

Since response.finished property is deprecated as of the newer node versions and another property i.e. response.writableEnded is currently used in place of it. So start supporting reponse.writableEnded in transcation's context. Also, the change is backward compatible as the respone.finished is not removed yet.
Fixes: #3428

Author: thesixpathguy

lib/parsers.js

@@ -131,7 +131,11 @@ function getContextFromResponse (res, conf, isError) {
 
   if (isError) {
     context.headers_sent = res.headersSent
-    context.finished = res.finished
+    if (typeof res.finished === 'boolean') {
+      context.finished = res.finished
+    } else {
+      context.finished = res.writableEnded
+    }
   }
 
   return context