Fix TS compilation error

Author: markerikson

packages/action-listener-middleware/tsconfig.json

@@ -21,7 +21,7 @@
     // "removeComments": true,                      /* Do not emit comments to output. */
     // "noEmit": true,                              /* Do not emit outputs. */
     // "importHelpers": true,                       /* Import emit helpers from 'tslib'. */
-    // "downlevelIteration": true,                  /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
+    "downlevelIteration": true,                  /* Provide full support for iterables in 'for-of', spread, and destructuring when targeting 'ES5' or 'ES3'. */
     // "isolatedModules": true,                     /* Transpile each file as a separate module (similar to 'ts.transpileModule'). */
 
     /* Strict Type-Checking Options */