Fix HTTP tests

apps/automated/app/http/http-string-worker.ts

@@ -1,7 +1,5 @@
 import * as http from '@nativescript/core/http';
 
-(<any>global).FormData = class FormData {};
-
 declare var postMessage: any;
 
 http.getString('https://httpbin.org/get').then(

packages/core/http/index.ts

@@ -33,7 +33,7 @@ export interface HttpRequestOptions {
 	timeout?: number;
 
 	/**
-	 * Gets or sets wether to *not* follow server's redirection responses.
+	 * Gets or sets whether to *not* follow server's redirection responses.
 	 */
 	dontFollowRedirects?: boolean;
 }