fix: fix import of AbortController and ReadableStream

Author: pi0

Diff for: lib/plugin.server.js

@@ -1,6 +1,6 @@
 import _fetch from 'node-fetch'
-import _AbortController from 'abort-controller'
-import _ReadableStream from 'web-streams-polyfill/ponyfill/es2018'
+import { AbortController as _AbortController } from 'abort-controller'
+import { ReadableStream as _ReadableStream } from 'web-streams-polyfill/ponyfill/es2018'
 
 const TEN_MEGABYTES = 1000 * 1000 * 10