fix(core_node): support agentkeepalive default export fallback and bump dependency to ^4.6.0

ts/00_commitinfo_data.ts

@@ -3,6 +3,6 @@
  */
 export const commitinfo = {
   name: '@push.rocks/smartrequest',
-  version: '5.0.2',
+  version: '5.0.3',
   description: 'A module for modern HTTP/HTTPS requests with support for form data, file uploads, JSON, binary data, streams, and more.'
 }

ts/core_node/plugins.ts

@@ -16,7 +16,7 @@ export { smartpromise, smarturl };
 // third party scope
 import AgentKeepAlive from 'agentkeepalive';
 const agentkeepalive = {
-  HttpAgent: AgentKeepAlive.HttpAgent,
+  HttpAgent: AgentKeepAlive.HttpAgent ?? AgentKeepAlive,
   HttpsAgent: AgentKeepAlive.HttpsAgent,
 };
 import formData from 'form-data';