http: initialize kAbortController to null instead of undefined

Author: akshatsrivastava11

lib/_http_incoming.js

@@ -93,7 +93,7 @@ function IncomingMessage(socket) {
   // Flag for when we decide that this message cannot possibly be
   // read by the user, so there's no point continuing to handle it.
   this._dumped = false;
-  this[kAbortController] = undefined;
+  this[kAbortController] = null;
 }
 ObjectSetPrototypeOf(IncomingMessage.prototype, Readable.prototype);
 ObjectSetPrototypeOf(IncomingMessage, Readable);
@@ -192,7 +192,7 @@ ObjectDefineProperty(IncomingMessage.prototype, 'signal', {
   __proto__: null,
   configurable: true,
   get: function() {
-    if (this[kAbortController] === undefined) {
+    if (this[kAbortController] === null) {
       const ac = new AbortController();
       this[kAbortController] = ac;
       if (this.destroyed) {